How can anything as basic as a sanding block be improved? Easily: saw a 3/8″ slot in one face, about 3/4″ from the side. Insert one edge of the sandpaper into the slot and wrap it around the block. Just your grip on the block will now keep the paper secure. I keep several sanding blocks on hand, some with square edges, others rounded to different radii. I also like to have blocks of hardwood, such as maple, and softer ones made of pine or poplar.
– Mike Michael