A good paint job completely revitalizes a room; but a bad paint job is obvious to anyone. Streaks, drips, and rough spots make the room look sloppy. But you don't have to be a professional to get a professional-quality paint job. Follow the steps below and your walls should look perfect.

1. Remove all switch and outlet plates. After you remove the screws from the plates, use a small piece of tape to attach the screw to the corresponding plate. This will help ensure you don't lose those tiny screws, and it will make reattaching them a lot easier later on.

2. Prepare the walls. Carefully inspect each wall from top to bottom. Fill all holes with a bit of spackle and then sand each patch smooth. Use a damp sponge or cloth to wipe the dust off the walls when you're done.

3. Use painter's tape. Unless you have a very steady hand, you'll need to use painter's tape to protect the surfaces you don't want to paint such as window sills, door frames, light fixtures, and baseboards. Apply the tape in short (arm's length) sections. Be sure to put a small piece over exposed light switches and outlets, too.

4. Lay down a drop cloth. Paint drips and splatters are inevitable, so be sure to lay down plastic sheeting or drop cloth over the floor. Plastic sheeting is cheap and disposable, and makes cleanup easy; however, it does tend to bunch up and shift easily as you move around, so it's a good idea to use a bit of tape to hold it in place.

5. Get your paint ready. One gallon of paint will cover about 400 square feet, and you'll need to purchase enough for 1-2 coats. Be sure to shake your paint can and use a stir stick to thoroughly mix it. Paint that isn't thoroughly mixed won't apply evenly, and can dry leaving unsightly streaks.

6. Invest in good supplies. You'll need a paint roller and a good, professional-quality paint brush. A brush with long, angled bristles will make it much easier to paint along edges and ceilings.

7. Start with the edges. Use your brush to paint the edging along the floor and the ceiling. Use short, smooth strokes when painting along the ceiling (this is why a high-quality brush is essential!). Keep a damp rag handy to wipe up any mistakes.

8. Paint the walls. Put a plastic liner inside a metal paint tray (another tip for a quick an easy cleanup when you're done) and fill the well about half full. Load up your roller by dipping it in the well and then rubbing it along the slopped portion to evenly distribute the paint. The trick here is not to overload the roller, and you'll know when you've done it because it will drip and splatter when you bring it to the wall.

9. Next, move the roller up and down in slow, V-shaped, overlapping strokes. Work in sections about three square feet in size, maintaining a wet edge as you move across the wall. This will help ensure smooth, even coverage. If you need to take a break, be sure to finish an entire wall before you do.

10. Apply a second coat if necessary. Once the first coat is dry (which usually takes about 30-45 minutes, or until the paint is dry to the touch), you'll know whether a second coat is needed. The paint will look thin in some spots, letting bits of the previous color show through.

11. Remove the tape. It's usually best to remove the tape before the paint dries. If you let the paint dry and then remove the tape, you may find chips of paint get pulled off as well. In which case, you'll need to carefully go back over some spots with your brush.

12. Clean up. Thoroughly wash your paint brushes, rinsing the bristles until the water runs clear. Lay them flat to dry on an old rag. Dispose of the roller, paint tray, and plastic sheeting, if used. Reattach switch plates and outlet covers.

Painting a room requires a bit of work and a lot of preparation, but the payoff—that intense feeling of pride and satisfaction—makes it all worth it.