I don't apply flawless finishes yet, but believe that I can, when desired. I get a lot of mileage from my sand paper from the technique described below.
After a few coats of sanded clear, sanding sealer, or Brodak primer - anything that starts to build up - I wet-sand with Dupont Prep-Sol, as suggested by Larry Cunningham. The paper still wears out, but much more slowly, and it does not clog or accumulate anything. The Prep-sol doesn't hurt the wood (no warps) and does seem to aid the sand paper in cutting the accumulating finish. In fact, you need to be careful how much or how long you sand, because you can easily remove too much. However, the finish is smooth. The Prep-Sol dries quickly - in perhaps a minute - while sanding. The photo below (I hope) illustrates the satin surface smoothness, after sanding with worn #400 or #600 paper. The typical residue should be visible along the nose tripler and is removed simply by gently passing a cloth over the surface. Sprayed clear completes the gloss, even with just Preval canisters.
SK