Deciding on the best finish for each woodworking project can be confusing. But there is one basic rule, which is: All woods must have a finish. Wood needs a finish for two reasons:

1. A finish protects the wood from sunlight, moisture, scratches and anything else it might come in contact with.

2. A finish enhances the wood -- it simply looks better when it has a finish.

One of the first things to decide is what sort of brush to use. Custom brushes are great, but they can cost about $25. These brushes have nice tapered bristles and probably won't shed too much -- but it's not necessary to spend that much on a brush to get a good finish.

At the other end of the spectrum are the cheap, throwaway foam brushes. Avoid these. They're full of air, and air creates bubbles in the finish. Look for a medium-priced brush -- something $4 to $6. Clean it up after the finish goes on, because this brush is good for more than one use. A few bristles probably will work their way loose on the midprice brush, so make it a point to run your fingers through the brush and pluck off the loose bristles before using it for the finish.

A mahogany end-table top needs a good protective finish. That's because the table will get a lot of use with people setting glasses on its top. For this, use a fast-drying polyurethane. This is an oil-based finish; stir it thoroughly and then apply it with a brush. Only dip about a half-inch of the bristles into the polyurethane, and then start working them into the wood. Strive for a thin coat, one that won't leave a lot of runs and drips.

To avoid brushstrokes, applying a coat of polyurethane, go back over it with one long brushstroke, holding the brush at a 45-degree angle and pulling it in just one direction. At the end of the board, turn the brush over and come back for the next pass. Then allow the oil-based finish six to eight hours to dry.

A different type of project, such as a table with a green stain on the sides, requires a different type of finish. The oil-based polyurethane would change the color a bit. Instead, use a water-based finish -- one example is Minwax Polycrylic -- that looks like skim milk when it's in the can. Use a synthetic-bristle brush to apply it. The bristles in a natural-bristle brush would swell out of shape from the water in the finish and could never be used again.

Dip about a half-inch of the bristles in the water-based polyurethane, and work it into the wood. It's particularly important to finish off with one-way long brushstrokes on a vertical surface, where the force of gravity tends to cause drips and runs. The water-based product needs to dry for only two to four hours.

Keep in mind that oil-based polyurethane will alter the color of a finish, adding a yellow tinge. This is fine with brown woods, but not right for color stains or some lighter woods.

Another option is tung oil, which is applied with a rag. Tung oil is a very thin form of an oil-based varnish, and like oil-based polyurethane it can leave a yellowish tinge. It gives a hand-rubbed, antique look. Use it for fine woods and furniture that isn't in high-traffic areas, because it doesn't offer as much protection as the polyurethane.

To apply, pour some tung oil on a rag, and work the finish into the wood in a circular motion. Finish by wiping it with the grain of the wood.

More advice:
- In order not to leave lint from the rag behind when staining, buy a higher quality of rag, or launder it first. Or switch to heavy-duty, lint-free paper towels.

- Lightly sand each coat of finish with No. 220 sandpaper. There will be very little visual difference, but it will remove the dust that's fallen down in there. Then take a sticky tack rag and wipe off the dust.

- In order to distress a piece of furniture, take medium-grit sandpaper, sand off some of the stain or the paint on the edge. That will imitate the wear on a piece that's antique. But choose the places to sand carefully -- don't sand somewhere that wouldn't ordinarily receive wear, such as the side of an end table.