Tap with the G36E . Most people don't realise that the first shot is always pinpoint accurate. If you can, tap your mouse, and wait for the recoil to settle down between shots. It's great.
In CQC , tap in bursts. 3-4 shots. Works wonders. If you wanna try another gun, try the M4A1, with an S3 if you can, and an Itech , (if you can) .