Originally Posted by jratuszn
When staining, does it help to lightly sand between coats?
This depends on the type of stain, IMO
Water-based stains will raise the grain slightly. You don't have to sand, but it helps if you want a mirror smooth finish later. A light sanding with 220 grit sandpaper will help knock down the grain that raised up. Use a sanding block for the best results. Don't sand it too much or you'll get light spots or unvenness in the finish. Also be sure to use a tack cloth afterwards to remove any sanding dust.
Oil-based stains rarely require any sanding after application. If you do decide to sand after applying oil stain, follow the guidelines above.
Polyurethane finished shouldn't be sanded IMO
. They are a self-leveling finish and should dry very smooth if you applied them correctly. Several very thin coats are much better than a couple heavier coats. Water-based Poly's will raise the grain slightly, but I recommend fine or very fine steel wool after every coat. Of course, follow that up with a tack cloth to remove all the dust. I only use sandpaper over polyurethane if I goofed up (runs, fingerprints, etc).
All this is solely IMHO