Reply by Loren

“weenie roller” it. A weenie roller is a narrow foam roller. I know
pro painters who swear by this method. Sand between coats to
level it, but the final coat should roll on real smooth.

You can paint a car with this method too. Done well, it looks just
like a spray job.

To cover grain use a grain filler, sand, then fill and sand again. Some
woods need it once, some twice.