Generally, I put aside the 1/16 sheeting idea and go with 3/32nds. Doesn't sound like a lot of difference till you realize its 50% thicker without adding much weight (if you choose your wood carefully) THEN you have a bit more to sand if you need to. I use one of those long aluminum sanding tools from Great Planes - the longer the better and stop sanding when I get rid of the high spots.

I've unsheeted a few wings to take out warps and its a lot better to do a replacement than try to sand out a mistake. With warped wings, you're not all that deep into the project yet and you should be checking the incidence down the wing. If you get one started, believe me it won't go away with trying to put the opposite sheeting in a reverse warp. You just waste wood.