1. Move a lot (seems obvious enough, but it's harder to hit what's moving)
2. Use strafing, rather than just turns
Most of it is really just hand-eye with aiming and making efficient movements
There are certain things in different FPSs that are specific to that game that can be useful to master, like crouch jumping in Half-Life.
A lot of it is just comfort, too. Like, I'm terrible with console-based FPSs because I've been using a keyboard and mouse my whole life, but some people like using gamepads/console controllers.
Strafing and movement is where you want to begin. Where i'd step it up from there is controller sensitivity, get good at one and move it up.
Also another thing that helps if you're playing stuff like Call of Duty, Counterstrike and Halo. Is move around the edges of the map, it lowers the percentage of people getting behind you. Which is how most people kill you, especially in COD.
Also if you are in the middle of a combat situation, don't reload switch to your secondary weapon and go to town. Reloading puts you at a complete disadvantage.
I'm a very aggressive FPS player so, take what you want. You could always try camping but I find that so boring.
On another note Subway was much bigger before Starbucks ever got large, I don't know if that is a canadian thing but its always been rampant here. I don't really get the hate for subway, its a much healthier alternative to stuff like mcdonalds and in n out. There **** isn't great but its not horribad.
That being said, its my bday tomorrow and I'm trying out this new bistro.
mmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmm