[Cooltad]

So basically, in this thread there are big tips and little tips, some for strategy, others for overall play and feel.

Just post whatever you feel is useful to know or useful to try to learn.
All posts of such content in this thread will be indexed in this first post if found to be very useful.

Better Rocket-Jumping
Considering many servers out there have sv_allow_wait_command 0, which disables most user-scripts, you must learn how to properly rocket jump on your own. Lucky you, this thread exists. Proper rocket jumping depends on what you want to do, but we'll stick with how to go both far, and very high with it. Take your choice rocket-launcher, aim down while running, and then fire it. But wait; as you're firing it, move the rocket-launcher all the way up, with the intention of pointing it at the sky. That's it, then you'll see yourself go extremely high and very far. Keep in mind, you must also use crouch, then immediately use jump, at the same time you do the rocket, where the crouch happens right before, and the jump happens during. After reading this, it should be easy enough to do. I recommend firing from the side of yourself going up, not in-front of yourself. With this info, only a small amount of practice should be required. It has to do with timing but what we've told you in this thread is half the battle already, good luck!

Better Engi Stabbing as Spy
Basically, don't you hate it when the engineer kills you after you sap their sentry? Or when the sentry kills you for killing the engi? Here is a solution. Wait until the engineer is in front/back of his sentry, when he is facing the sentry. Then stab him, quickly switch to the sapper, and place it on the sentry before it is able to shoot you. This isn't hard, you just need to be good on your trigger-finger.

How to Piss-off an Uber'd Person as Pyro
Don't you hate it when that medic and heavy/demo/soldier fuck your shit up, then force you to eat it? Well, Pyro's are as good at slowing down Uber teams as level3 Sentries are, which is saying a lot. Every second you hold them off from proceeding, makes their time more and more limited to how much they can screw your team over. Simply equip any flamethrower that allows for the air compression, then push the uber'd soldier/heavy/demo repeatedly. You must be good at this, so you can hold them off for as long as possible. If you're extremely lucky you'll hold them off long enough to kill them when their Uber runs dry. This works best is the Uber'd person is a heavy, which in most cases it is.

Correct Weapon-Firing With Any Falloff-based or Projectile Weapons
This includes the flamethrower, pipe-bombs, rockets, arrows, and syringes.
What a lot of people do is this: When your target is moving, they fire at where the target is. Wrong! You're instead supposed to do this: Do not fire at where they are at when they are moving; instead, fire at where they are going to be. How far ahead you must aim depends on a number of things, but a general rule of thumb is to progressively aim further ahead of them the closer they are to you. If they are right near your face, fire very far ahead of them, and it should hit them. This tip is especially useful for demo's and pyro's.

Useful Bindings
If you need to, enable console access by going to Options, Keyboard, Advanced, check Enable Developer Console. Then press ~ to access the console. When in the console, two very useful binds are this, you may copy-pasta them into console:
bind t "build 3"
^Allows you to build a sentry easily.
bind f "+use"
^Allows many neat things on various maps, such as pressing f to move an object, or press a button.