Areas you do NOT want to stipple, where stippling has no benefit and just rubs you raw whooting, IMO:
-top of hte back strap, where the webbing of your hand goes.
-underside of the trigger guard just ahead of the front strap, will rub your middle finger
-thumb rests (top of sides of grip area).
Stippling is not that rough, just use very fine dots. Some say you should n't do the front strap b/c it makes it harder to shift your rip to operate the mag release or slide catch.
Do stipple:
-flat parts on the frame, where you off hand thumb rests
-front of trigger guard
-forward half of the underside of the trigger guard
-lower 3/4 of the back strap
-in general, the radius of the back strap.
There was an interesting article recently in the blue press that talked about asymetric placement of grip tape. I think he said he liked it on only one side of the grip...