This a fiendly post to share my personal Tips & Tricks learned from shooter games and real military discovery type documentaries. Including "Top Sniper Season 2" and "Special Ops Mission: Season 1"
#1 The peek-a-boo technique (barely peeking in and out of cover once or multipule times).
#2 Cat and mouse technique (reveal your body to the enemy and run behind cover turn around and kill him if he follows you).
#3 If shooting out of a window dont let the barrel of your gun hang outside of the window.
#4 When sniping I perfer a sniper shooting technique called "Traping" Meaning hold your crosshair over the spot your enemy will run into and shoot him as he runs into your crosshair.
#5 Keep your back against something solid or bulletproof.
#6 Using something called a swivel head technique. Meaning to keep moving your head around alot left and right as much as possible.
#6 If your in intense and clan scrim type matches with freinds or clan members sometimes requesting silence so you can all hear your enemies movements better.
#7 Follow your freindly but not to close not to far away and if the dies, try to know where they got shot from by looking at your team mate.
#8 Pay close attention to bullet tracers and try to find out where your enemy is shooting from.
#9 Try to discovery what the best "Tactical Terrain Approach" is for attacking your enemy.
Hardware Tips
#1 some video drivers might help your computer perform better than others.
#2 I can not stress enough that you should without a doubt have a "Gaming Mouse" There is a diferance from a regular mouse and a "Gaming Mouse" Some gaming mouses reduce random drifting stalls and can if set up correctly greatly increase the precision of your aim.
#3 The higher you can get your fps the better aim you will have. Fraps.com will give u a free program that will show your what your fps is in games. Below 20 fps could be hurting your aim really bad.