The type of finish you apply to wood depends on what the wood will be subjected to and the effect you want to achieve. First, decide whether you want to stain the wood. If you like the wood's natural color, no stain is necessary. But a stain, particularly one of the penetrating varieties, can enhance the beauty of the grain. Use one that's only slightly darker than the original shade if you don't want to change the color that much. Stains can be applied with a brush or a clean rag. Make sure you always apply stain with the grain and wipe off any excess. For finishes, you have two basic choices: oils or surface coatings. Penetrating finishes like oils soak into the wood and harden the fibers. This gives a vibrant, natural finish, but offers very little protection against abrasion. Getting the best results from oils is largely a matter of patience and elbow grease. Dip a clean cloth in linseed or tung oil and rub it on the wood. Alternate back and forth with circular motions to make sure the oil penetrates completely. Rub 10 to 20 minutes for each square yard of wood. Let it soak in for a few minutes, then use a polishing cloth to bring it to a luster. Wait several days to a week. Then repeat the process. For optimal results, at least five coats are necessary, each a week apart. Surface finishes offer more protection, but don't allow the natural grain to show through quite as well. You can choose shellac, lacquer, varnish or polyurethane, each of which will give you slightly different results. When applying any of these, it's important to avoid air bubbles. Use a clean paint roller pan to wipe the brush, rather than the edge of the can. Apply with smooth, even strokes along the grain. When it's dry, finish it with very fine sandpaper or steel wool, remove any dust, and apply a second coat.