First of all, I want to admit that I hate sanding.  I build a little of everything RC, CL, and FF.  I have a 3M soft foam hand sanding block that uses hook and loop sandpaper.  Like this.
http://www.amazon.com/3M-05742-Hookit-Soft-Block/dp/B00063UCXG
 I only have 220 grit paper to fit it and wanted some other grits but being penurious, balked at buying a whole roll of single grit paper at the local auto supply for $38.00.  Then the lightbulb went off in my head.  I stopped by a local arts and crafts store (Michael's) and found pre cut pieces of felt for $0.39 each that just happen to be cut to the exact size of a full size sheet of sand paper.  (They also have have a peel and stick version for $1.09/sheet) So buying 2 pieces I returned home to the shop and got out my trusty can of 77 spray adhesive and coated the back of a sheet of 320 grit paper and stuck it to the piece of felt.  After waiting about 5 minutes I cut a piece to fit the block and low and behold, presto-change-o, it sticks fine to the block!  Even better it comes off fine in one piece! And it sands a treat!  This opens up a whole new venue of custom made hook and loop sanding blocks.  Sticky back velcro is also available in different widths and can be stuck to different densities of foam or wood to make them any size or shape you want!  The scratchy side goes to the block and the felt to the paper. Works with dry or wet/dry papers.