i like killing hopping dudes while staying stand, i dont move and got fast headshots...so my tip is that you should choose random firing spots after respawn, and grab the gun u can use the frikin best, aim at the head...i am pretty surprised that i sux so much hard now with snipers, and sniping using the ACOG's is very easy fur me...
anyways, my tip is just make kill by kill, not make combos, but if u have a good gun and too much foes around gt an unb lol