Russ, Get some pieces of 1" dense blue insulating styrofoam, and you can shape them to help sand curved surfaces. I also use soft urethane foam for large contoured areas, the foam keeps the pressure very even on the surface - very usefull for cutting through rough putty patches back down to the surface. i have made dull points, inside curves for sanding curved surfaces, or strips for sanding a fixed piece, kind of like buffing a shoe with a shoe-shine cloth.
Also indispensible are those rubber sanding sticks that look like big black nail files, come in all different grits.
Of course i wrap the sandpaper around pencils, straws, or just make a tube out of it.
If you fold fine a small square of emery paper twice, the sharp corner (where the middle of the square was) is great for 'digging' into tight corners.
I guess when you get down to the 1000 grit or so you get pretty excited about painting! --errr, well, I used to in a former life anyways.....lol
Dom