The main thing I would like to focus on here is priming those grenades. Priming lets you take out an enemy before he can destroy you. There are special codes and some scripts that make it easier to time it but I prefer the good ol' fashion way; 1 beep, 2 beeps, 3 beeps, boom! Sometimes it is hard to time it correctly if you are using a slow modem so simply count: '1 Mississipi, 2 Mississipi, 3 Mississipi, boom!'. I usually toss the grenade at 3 beeps when fighting at close-range. If the enemy is very far away, you sometimes won't even need to time it, just toss. Keep in mind that holding a grenade for too long is suicide so practice in an empty map before kicking arse. Have fun!