3M has a new sanding material that I really like. It is called Sandblaster. It is a sanding film for use wet or dry. I am using 320 grit wet. It is translucent- almost transparent, so you can see the surface you are sanding through it (at least somewhat, the waste paint and such does cloud the view, of course). It is supposed to last much longer than wet or dry paper, and that seems to be the case. Also, it seems to require less frequent cleanout of the material during use. It is quite flexible, nice on curves, even compound curves.
I am using it currently on seams of a cylindrical launch vehicle booster with bad seams. I am clamping down the part, and using a strip of the stuff across the seam in the manner of a shoeshine cloth.