Molding can frame a room and its elements in any number of ways, giving more attention to the room's components.
1. Choose molding that complements your existing trim. If your trim is oak, for example, choose oak molding. If it's made of expensive or inaccessible wood, consider staining a less expensive wood to match existing trim.
Calculate the amount of material needed, and as you shop select the best-looking lengths. Some moldings, especially those that have been on a showroom floor or have been used as samples, can show signs of warping or discoloration. Purchase enough to avoid piecing any of the lengths (except at corners). This will result in more waste, but makes for an easier and better-looking project.
2. Use a long level and mark where the molding will go. If you're installing a chair rail, for example, measure from the floor and place the top edge of the tape at the height chosen for the rail. Use this height as a reference for other measurements.
Place painter's tape on the walls where moldings will be installed. Check for level placement and spacing. Mark the outer edges with a pencil, to provide a guide for molding placement, then carefully remove one section of tape at a time, just before the molding is installed.
3. If you're painting your molding: Apply a primer coat using all-purpose interior primer. Let dry. Sand the wood lightly. Then apply the final paint color, using a semigloss or eggshell finish.
4. Measure and cut pieces to length using a miter box or compound miter saw. Measure to the outside corners. Cut one corner first, then make the final cut.
TIP: Cut from the thinner edge of the molding to the thicker edge. The outside edges are more likely to splinter. Lightly sand splintered edges.
5. Glue moldings to the wall. Apply glue to the back of the molding. Use glue sparingly, dotting the material every inch or so, or drawing a thin, wavy line of glue from one edge to the other. Use your pencil markings to position the molding on the wall.
6. Secure the molding to the wall with finishing nails. First, drill nail holes, using the size nail that will anchor the piece to the wall. Then tap in the nails.
7. Fill gaps in mitered corners and along edges with painter's caulk.
8. Touch up paint, if necessary.