i normally rev it to 2.5k or so if i wanna take off smooth aswell. It's one of the down sides of a grippy clutch/ lightweight flywheel - its really easy to burn the clutch when reversing up hill aswell (i just generally avoid it).

To answer your question (friends question) i normally keep the revs at 2.5k for 1-2 seconds to get the car moving then release relatively quickly after that, its just a matter of playing around with what works for you