practice makes perfect.(well better anyway)
having quality mice n keyboards etc etc dont make no difference, im runnin a 3 button rollerball mouse and an old shitty keyboard n i still finish top regularly.
get to know the maps, while your dead, spectate the players who are top of the list, see what they do, where they go.
get a set of headphones and have them up loud, learn to use walk slowly when theres only a couple left on the map, you'll be able to hear a player scratch his arse from a mile away.
get your Autobuy set up, always be ready to move when the counter hits 0, the people who go first are the people who get into the best positions first n get the kills.
personally, ide say familiarise with the AWP (sniper rifle), you get good with that and a deagle you'll be practically unstoppable. you'll get people calling you a noob for using it but its there so use it.
myself my key set up is as follows
W - forward
S - back
A - strafe left
D - strafe right
shift - crouch
ctrl - walk
zxc - radio commands
f - disgard weapon
e - previous weapon
r - next weapon
v - flashlight
mouse button 1 - fire
mouse button 2 - secondary function (zoom)
mouse button 3 - reload.
