To display numbers along with dots for latency on a server type -numericping in the shortcut's target line.

To turn off background sounds so you can hear footsteps and real fire better type stopsound in the console.

Depending on your video card, this may or may not help your framrate much

Open your console
Type in command:
fps_max 100

*NOTE* 100 can be substituted for anything, but I use 100 and get about 70-85 FPS

*NOTE* Depending on current settings, the results could be anywhere from huge difference to minor change in shadow

Open console
type in lightgamma 0
play!

This must be entered in every time you start your game, so it helps to bind it to a key!