Sand the wood surface smooth, ending with fine-grit sandpaper
Remove all dust with a vacuum, tack cloth, or lint-free cloth
Stir the polyurethane gently; do not shake it
Choose a clean, high-quality brush, foam brush, or applicator pad
Apply a thin, even coat along the grain of the wood
Avoid overbrushing and puddles
Let the coat dry completely according to the product instructions
Lightly sand the dried coat with very fine-grit sandpaper
Remove all sanding dust before the next coat
Apply additional thin coats, sanding lightly between coats
Repeat until the desired finish is achieved
Allow the final coat to cure fully before use