Test on the actual wood first
Stain behaves differently on every species. Cherry goes redder, pine goes blotchy, maple goes patchy without a sealer. Always test on an offcut from the same board you are finishing.
Make up a test piece showing one coat, two coats and with and without sealer. Fifteen minutes of testing prevents a whole project going wrong.
Apply stain and take back the excess
Work in manageable sections. Flood the surface, let it sit for a few minutes, then wipe the excess off with the grain using a clean rag.
The longer it sits, the darker it goes, so keep the dwell time consistent across the whole piece or you will see the difference in the finished job.
Build thin coats of polyurethane
Wait the full recoat time — usually four to six hours for oil-based polyurethane. Applying the second coat while the first is still soft traps solvent and produces a wrinkly, permanently soft film.
Thin coats are stronger than thick ones. Three thin coats will outlast two heavy coats every time.
Sand between coats and finish
Lightly hand sand with 320 grit between coats. You are knocking down dust nibs and giving the next coat something to key into, not removing finish.
After the final coat, let the piece cure for several days before putting it into service. Wipe-on polyurethane stays softer than it will become for about a week.
Safety with solvent finishes
Oil-based stain and polyurethane are flammable and their fumes are harmful. Work with cross-ventilation, wear nitrile gloves and a respirator, and store soaked rags in a sealed metal can or submerged in water.
Spontaneous combustion of finish rags is a real and common cause of workshop fires. Never leave them crumpled in a bin.
