Finishing

Remove glue splotches before staining (stain will not color glue).
Use a low-angle "raking" light to identify glue splotches and blemishes.
Seal resinous knots with a shellac-based sealer.
Apply a filler to open-grain woods (e.g., oak) for the smoothest possible finish.
Use a test strip of wood to assess the color and quality of the stain and top finish.
Reduce stain splotching in pine by applying a washcoat sealer or a gel stain.
Sponge wood and resand when dry to minimize grain-raising from water-based finishes.
Sand end grain to a finer grit to prevent excessive stain darkening (or use gel stain).
Apply a washcoat to end grain to prevent excessive stain darkening.
Finishes containing oil (including varnish) yellow over time.
Most woods darken as they age.
Arrange pieces horizontally to reduce runs and sags (especially when brushing).
Use shellac or lacquer if repairability and reversibility are most important.
Use water-base finish for low toxicity, non-yellowing, and ease of clean-up.
Use lacquer or dewaxed shellac for the best clarity and rubbing qualities.
Use pure oil finishes for the "natural" look (at the expense of protection).
Use polyurethane if you want an inexpensive, very durable, very protective finish.
Use spar varnish or paint for the most durable outdoor finishes.