Or you can buy a simple rubber sanding block at almost any hardware store, paint store or home center. But for the ultimate ...

The Rubber 3M Sanding Block. ... When sanding a curved surface with the soft side, such as the contour of a crown molding, the molding’s shape will guide the block on a straight path.

Sanding Sponges Offer Soft Touch for Contoured Surfaces. By Bill Esler April 30, 2014 | 4:45 pm CDT. Click ... The utility and acceptance of sponges, pads, and sanding blocks, ...

Wrap a piece of the softened 1,000-grit sandpaper around a thin, rubber sanding block if you're going to be working broad, flat surfaces. Otherwise, you can just fold the sandpaper in thirds.