Ask the teenager for color and paint ideas. If he wants a color you consider outlandish, compromise by painting an accent wall in that color, and painting the other walls a more neutral color. The Paint Quality Institute recommends using "high impact, bold color" on accent walls.
Consider the ceiling as a "fifth wall." Rosanne Dunkelberger, writing in Tallahassee Magazine, suggests painting the ceiling a lighter shade of the wall color, or creating a dramatic effect by painting it a very deep color.
Choose colors that match or complement other design elements in the bedroom, such as favorite posters, the bedspread or window coverings.
Purchase small cans of paint in the colors you've chosen to test them on the walls first. It can be difficult to predict true color from paint swatches.
Remove as much of the furniture from the bedroom as possible before starting work. Wash the walls and trim with mild detergent and water, then protect the floors with drop cloths. Cover the remaining furniture with plastic sheeting.
Fill holes and cracks with patching compound and caulk gaps around the woodwork and in corners.
Paint the ceiling first, using a roller. Paint the trim with a brush and allow it to dry.
Mask the edges of the ceiling and trim with blue painter's tape. Cut in all the edges first with a brush, then roll the walls. Do a second coat of paint if you're changing either the color or the sheen. If you are painting an accent wall, paint the other walls first and allow them to dry for at least 8 hours. Tape the edges carefully with painter's tape and paint the accent wall.