Your paint is mixed and your roller is at the ready, but make sure to plan a strategy before you get started. Work from the top of the room down, starting with the ceilings. Planning a bold focal wall? Paint the adjoining light-color walls first. Don’t worry if you get paint on what will be your accent wall—the dark paint will cover up whatever lighter paint found its way there. After the lighter wall dries, tape off that edge so the dark color doesn’t bleed onto your new paint. If you’re covering up dark walls with a brighter hue, plan on three coats: your primer, plus two coats of the new color to ensure nothing shows through.
Tackle one wall at a time. Take a brush and “cut in”—paint along the molding and the corners from top to bottom—while your friend uses a roller to cover the main expanse of the wall, staying away from those more precise spots. When applying paint with the roller, use long strokes in a W pattern for ample coverage (and to avoid those pesky roller marks). Once the wall is dry to the touch, it’s ready for a second coat.
If you are painting the trim, remove the painter’s tape and wait for the walls to dry, before applying tape to the walls. Start with the trim closest to the ceiling, moving on to door and window frames, and finally the baseboards.