gearing will all depend on what you are trying to accomplish.

if you are street riding looking for that little extra umph...you can do -1/+1-2

track riding will all depend on what track you are at and you will want to keep a hand full of sprockets to change out to suit your lap times and track.

stunting will depend on whether you want to learn on stock gears or go +15 in the rear or whatever will help you accomplish your goal.