Forego fine grits
If you're sanding up to 320, 400, or even higher grits before adding a film finish, much of that sanding tedium goes to waste. Instead, sand to 150 grit for unstained projects and 180 grit for those receiving a pigment stain. With the time you save, rub out your final layer of film finish using 0000 steel wool or a synthetic substitute. This knocks off any remaining dust nibs and leaves smoother surfaces. With oil finishes, sand the surface to 180 grit before applying the oil, then sand with 400-grit abrasives between coats for a smooth surface.