Baiting:

Baiting is when you have another player take the attention of a group of titans off of you and instead onto them, giving you a clear and easy shot at the nape. You can use this to great effect in any of the runs.

Shift Locking:

Shift locking is a mechanic in Roblox itself and not just Attack on Titan Downfall. If you hit escape to enter the pause menu and then go to 'settings' you will find the top option labeled 'shift lock switch'. This is disabled by default and you will have to turn it on.

Once shift locking is enabled, close the menu and then press 'shift'. This will lock your third-person camera movement to your mouse and you will no longer need to right-click and drag to adjust it as needed.

Learn How to Move with Tethers:

Your tethers are your main form of movement in this game and it is near impossible to kill titans without utilizing them. That's why it's important to learn how to use them to the max of their abilities.

-Alternating: Alternating between your tethers is a good way of maintaining constant control of your movement, shoot one, let that one pull you, let that tether go, and then shoot the other, switching between them.

Here is an example of moving using alternation:

And fighting titans using alternation:

-Use Your Gas: You can press and hold space, which will cause your character to use gas and give you a speed boost. Hold space pretty much any time that you are not moving using your tethers.

Those are all the general tips that I know off the top of my head, I might come back and update this with more advanced tips later or make an entirely new guide for advanced movement.