Some random fun stuff in gunbound to look cute (or pro).
Most of it is very old news but some I found only recently.

Armor -

Mini-SS: use about 1.7 bars of power for a very late SS that
opens right in the opponent's face.
Angle 80 travels just under 1/4 screen.
I guess max distance happens around angle 45 at a bit over half
screen. You must be very careful of height differences where the
enemy is above you. I don't have a lot of experience with this yet
but I guess the rule of thumb to use is angle 78 is about 1/4 screen
and angle 60 for half screen. 1 bit past half screen is max range.

Long range shotgun SS: it's not really shotgun but at angle 32, using
about 3.05 bars of power will allow you to send an SS at an enemy
exactly 1.5 screens away from you. Because the angle is flat and the
power is high, it covers the distance quickly and barely opens in
their face. Watch for elevation and use 3.1 if they're above.

Hurricane SS: It's not super rare to be in a situation where you and
an enemy are very close and a hurricane appears on you. It can seem
kind of lame because hitting them for high damage seems risky, even
a 1 inch shot can be screwed up with hurricanes. A trick I learned
is to get a pretty high angle (80's?) and fire your SS with barely
any power. It will slowly go up through the hurricane and stay in
the air so long it opens before it leaves the hurricane.
When it does leave the hurri, the power is almost nothing, and as
long as the wind doesn't screw up the shot, it should drop straight
down next to the opposite side of the hurri. That's a pretty sure way
to land a lot of shots with a lot of mobiles vs an enemy in that
position. Don't try it outside the hurricane or it will bounce off
at such low power :o

Dual+ angle rape: it's easiest when wind is against you. Fire a
dual+ in the wrong order, with shot 2 first. Try to get shot 2 to land
just at their feet at a fairly high angle. If done right it misses a
bit and they drop into the hole it makes. Then your shot 1 follows
and makes a big underground hole. If it hits just right they will be
left with no angle to shoot at you.

Boomer -

Mini-SS: From Rearview... use 1 bar of power. 80 lands right in
front of you. Every 5 angles lower makes the shot travel 1 mobile's
width further. Lowest recommended angle is about 50. Again watch
elevation, use 1.1 or 1.2 bars vs higher enemies. The nice thing about
this SS is that unless you're dumb and don't use enough power, there's
a lot of room for error. You can miss a bit and still hit for 300+
damage. Max range is maybe 1/3 screen at angle 50.

High power backshot: From Honghong, use 2.5 bars of power and
a low angle. You can safely go up to 2.9 bars without changing the
landing position of the boomerang much and without risking the shot
dropping down and hooking. Looks coolest when you use it to touch
a faraway force or thunder before the shot bends backwards.

Full power backshot: I still don't have this down. The idea is to use
the high power formula, then measure distance differenly when deciding
on the final angle. Supposedly 1 screen distance is made up of about
20 angles when doing full power backshots (it's 30 parts using the
2.5 bar method). My experience is it's sometimes more and sometimes
less than 20 parts depending on wind direction. S4yo says to try
using 2 angles less than the 2.5 backshot method. It will help to
memorize that with 24 wind diagonal (45 degrees up wind) you can
hit half screen with 50 full.

Thunder Bunge: This is one of my favorite old tricks, I saw it early
when I was playing and rarely afterwards. In fact I saw it so long
ago that the enemy was bunged through Metamine, which doesn't have
thunder or force anymore (although I hear they have it in korea GB).
All you have to do is make it pass through lightning and move boomer
or control power carefully so that it's a perfectly centered hit.
Each hit of the thunder sinks the enemy lower and lower, and you
should be getting 8 hits from your dual. I've seen enemies pass
through adiumroot before from this. I'm sure they can be bunged
through metropolis and nirvana too. At long range, like a 1 screen
distance shot, you must plant the boomerangs a little in front and
miss the enemy. The shot digs a deep pit and the lightning strikes
erode the land under the enemy and drop him in the pit.
I'd never believe an 81 full shot could bunge like this until I saw it.

Facial SS: I need more testing with this. Here's the best I've come
up with for half screen and 1 screen timebomb SS.
Half screen: 40, 1.4 bars
Full screen: 18, 2.5 bars.
You can also do 20, 2.5 but it doesn't look as cute.

Inside-hurricane hook bomb: Ever see someone using boomer and
sitting inside a hurricane, and they fire upwards into it... wind is
against them, and when their shot exits the nado it seems to have
no power and just gently hooks down to hit an enemy on the other side?
I don't have the formula for it but it depends on wind and stuff
anyway. Different angles make the shot exit at different heights
in the hurri, and you choose the height that you think will cause
the shot to drift diagonally into the enemy. A simple rule to start
with is to pick the angle you'd use for a normal hook at lower 2 or
3 degrees when up close.

Angle ruining with shot 1: This needs a very lucky situation where
the enemy is up against a very high, steep wall to get angle. If you
are pretty sharp with your formulas in 0 wind you can not only control
where your shot will land, but also try to make it hit in front
or behind a bit. Land shot 1 in front a bit and you can ruin the
angle of bots like turtle who love to stick to high walls.

Weird long shotguns: On many maps you can shotgun across 1.5 or even
2 screen distances if you just take a minute to memorize some basic
angles. For an enemy 1 screen away and level with you, angle 5 is ok.
For 1 end of metamine to the other (from the far left or right inner
slopes) is about angle 11. That's over 2 screens. You can go from
one wing of dragon to the other with maybe angle... 16 I think.
From 1 end of adiumroot to the other is something I still need to
research. I want to say it's about 20?...
Basically, don't be afraid to try long range shotguns because they're
really easy shots and very sloppy, you can aim almost by just using
your eyes (and a ruler :P) and a little wind is not a major problem.
The enemy makes a big target when the shot is approaching at a flat
angle, and your misses are easy to compensate for. This is also one
of the easiest and most reliable ways to make sure shots through
hurricanes, in those situations where you must hit a dual through
a nado I use shotguns a lot. Even though most people look down on
shotguns, nobody complains at 2 screen distance shotguns. Memorize
shotgun angles for unusual maps that nobody else has memorized,
like sea of hero or metropolis. People will think you're crazy pro.
Props to Talent for his metamine shotgun guide.

Sate -

Cake SS tag trick: I love this trick, it's the most fun way to do
bunge games in avatar off. It works like this. You either have a
partner playing cake, or have cake as your tag. You are sate and fire
an SS that 'accidentally' misses just a little bit behind the enemy.
It helps if the map is adiumroot. There's now a hole all the way
through the map and the enemy's in front of that hole. You can't push
them off with cake SS anymore, but a skilled partner can fire JD's
shot 2 right into the back of the hole your SS just made.. and it
sucks the enemy down the tube for an easy and funny 2 turn kill.
The same can be done with missed boomer duals, but I think Sate's
SS makes it easier.

Low angle shotgunning: When on the right and shooting left, low angle
shotguns are quite strong. Sate always wants his shot to land a bit
to the right of the enemy, so when shotgunning from the right your
tracer will naturally stop when it hits the right edge of their body,
and your shot 2 will rain down for full damage. This is important to
know because it allows for easy and reliable SS shots from right
to left (while shotgunning the SS left to right often results in a
half miss or almost 0 damage). You can even try SS through hurricanes
as long as you're on the right side, you'd be surprised at how easy it
is to hit on your first try. People will think you're pretty sharp if
you land a tracer on the enemy through the hurricane and all the
lasers from your shot 2 miss... but your SS on the next turn hits
for full damage.

Raon -

High angle babies: Old news to raon pros, fire shot 2 at angle 89
full or angle 88 a bit less than full and your babies can both come
down and hit the opponent's core for full damage. When wind is against
you, I think it's possible to use even lower angles to do it.

Baby poop: Sometimes the enemy is next to you in a small pit (maybe
a pit you created). You can't get a low enough angle to hit with
raon's infamous shotgun babies. Instead, if you climb down the front
slope of their pit and then turn around, you'll be facing pretty much
straight up. If you can get an angle 89 backwards you can fire babies
with low to medium power and with an accurate center hit they'll both
explode. If wind is blowing towards the enemy, you can use angle 90
or lower to get the same effect. If the pit happens to be deep and
you can put raon directly above the enemy, it's possible to just tap
shot 2 with angle 90 and let the babies pass through your body and
smack theirs.

Raon slip: Shotgun babies at the underside of thin land and they
will teleport to the other side of the land (and hit the enemy) as
long as the ground you're trying to slip through is only a few
pixels thick.

Raon slip 2: If lightning or thor is out, you can shotgun through
slightly thicker bits of land, thor will smash some of the ground
for you and make it thin enough to allow the raon slip to work.

Raon bounce: you can bounce raon's babies off the ceiling and cause
them to fall straight down onto an enemy and explode for full damage.

Nobrainer SS: Some raons use SS right away so that it returns later
in the match, others wait until they need a sure shot for a kill, and
others wait until they can try ruining the enemy's angle once they're
in a pit. I like to use it to make difficult shots quite easy.
With the SS, long range hurricane shots can be sloppy, and you don't
have to work to do 250+ dmg to an enemy who is hiding behind a wall
of dirt when the wind is strong. (which makes using babies harder).
I especially like nado SSes because you do useful damage but can also
get a preview of where your next shot will land if you switch to shot
1 or 2 next. It's like a test shot that still does good damage.

Angle fukkage: When the wind is against you fairly strongly, fire
a dual shot 1 at the enemy with a fairly high angle. Aim to plant it
just behind them. I usually use 2.5 bars of power (the fixed power
formula) to try to measure the shot. The idea is to have the shot
blowing towards you a bit by the time it hits the ground. So it will
land behind the enemy and be moving towards you and make a nice
diagonal hole (the bottom of the hole leans towards you). If the
dual knocks the enemy into the hole, they will have a big cliff of
land leaning directly over their head and cannot shoot out. Laugh
as lightning spends the next 2 or 3 turns trying to dig through it.

Turtle -

Type 3 SS: I credit to Ramza for showing me this
(indirectly with a screen shot). It works sort of on the same idea
as the armor tornado SS trick. You fire your SS with an upward angle
and barely any power. It spins through the hurricane very slowly and
opens up halfway around. When it exits the other side, all the balls
are clustered in a vertical line and drop directly on the enemy, if
you're lucky enough to have an enemy right next to the nado on the
other side.

Mage -

Is there anything fun to do with mage? I can't think of anything.
The best you can do is look for situations where you can direct hit
someone with an SS and also take out another nearby bot's shield for
high total damage. You also have a nice shot 1 that makes big holes
so try to plant a high angle shot 1 just in front of the enemy
mobile to ruin their angle and possibly cost them a turn.

Nak -

High angle scariness: High angles are actually useful for nak, not
just showing off. The higher your angle is when the shot enters the
ground, the less distance it has to travel forward while underground.
Anyway the basics of nak high angling are: Angle 85 hits the front
side of a mobile who is positioned half a screen away (so 85 is good
enough as a half screen distance measurement). 80 lands quite a bit
in front of 1 screen, so exactly 1 screen distance should be counted
as 79 with almost full power, not 80 full. A simple wind adjustment
trick: If you already know the high angle measurements for 0 wind,
and the wind is now blowing against you, just use this formula:
lower your angle by 2/3 of the wind. ...So if wind is blowing at 21
against you, just lower your angle by 2/3rds of 21, which works out
to 14 angles. A half screen shot would go from angle 85 to angle 71.

Angle screwing: There are so many ways to do this with nak.
Easy method (close combat): If the enemy is already in the front of
a small pit, hang your ass out over the edge of the pit and drop a
dual shot 2 with 0 power (or very close) on the front of their mobile.
They will be put into a deep hole and if their climbing ability isn't
awesome they may end up with no angle. If wind is blowing against nak
a little bit this works even better, as the shot travels backwards
and makes the hole directly under nak's body.
Easy method part 2 (close to middle range): If the enemy is on the
front of a tall slope, get a low angle and shotgun shot 2 through
land so that it comes out the other side of the slope. The hole
that you make can completely screw their angle and force them to
shoot through lots of land. Sometimes you can't easily make shot using
shot 2 to accomplish this. A good nak player will recognize the
chance to screw angle and use the SS to do it instead.
Trick method: A low angle shot 2 is also great at ruining angles
on maps with lots of little hills like metamine and miramo town. You
can almost shotgun your shot 2 across the screen and clip the
backsides of the small hills that your enemy is using to get angle
against you.
Harder method: If you get good at high angles, after one successful
shot you should know fairly accurately where the next shot will land.
You can try to make the next shot hit a bit in front of the enemy so
that instead of hitting their middle for max damage, it hits their
front to ruin their angle. The easiest way to do this is to just make
the same shot you did last time but walk backwards a little bit before
you shoot. Dual to screw their angle more thoroughly (but usually
that means sorta low damage for your high delay dual).

Grub -

Angle fukkage: Old news to grub players, use lightning with shot 2
and hit the enemy with a nicely lined up high angle shot 2. You must
land the balls directly on them, not let the balls roll into them.
If done correctly the lightning makes a tiny 1 cm deep narrow pit
and the enemy will be inside it and may not even be able to get a
decent angle, or if they can they're forced to shoot through dirt.

High angle SS: Not everyone understands that grub's SS 'countdown'
doesn't begin until it hits land, so it's fine to fire high angle
lobs and full power SS shots at the enemy, as long as they're in the
kind of pit where you know the SS will land for nice damage. If the
enemy gets knocked into a thin hole made by missed boomer shot 2's or
sate's SS you can get really good damage by trying to drop the ball
directly down the chute so that it doesn't touch the walls going in.

Flat land SS: SS on flat ground?! yeah, you can. On perfectly flat
land if you're close to the enemy (like they're on one of the small
hills on metamine and you're on the slope next to it) you can try
for a very high angle and fairly low power like 1.7 bars or so. If
the shot doesn't have to move forward much it will bounce off the
ground and keep bouncing while moving forward very little. It's good
for 400ish damage if done correctly.