I have painted white trim (casing and base) that has been recently installed. I am looking for advice on what to fill the nail holes with. Keep in mind that the woodwork is already painted. I am also looking for something to fill a few of the miter joints with. (some I just could not get that tight). I used Sherwin Williams Pro-classic waterbased and am looking for a product that I DON'T have to prime and DON'T have to sand since the trim is already painted. Thanks for any advice!
If the nail holes are small enough, then most anythig won't really need sanding. Just run over them with a damp sponge. You can probably get away with not priming little nailhole spots, but blending the paint might be tricky. You can try a Q-Tip to apply the paint.
To make a really nice looking finished job and to make painting easier in the future use matching latex caulking to fill the nail holes and miters. Don't forget to caulk where it meets the wall. Use a clean damp lint free cloth to wipe the caulking in the joints and a stiff sponge for the nail holes. Be sure the caulk is the printable type.