Following a logical order for any paint project does matter, Henrique says. “It saves time and protects your work. You won’t be brushing up against or dripping paint on wet surfaces, so you won’t have to redo them.” His general approach is to work top to bottom, left to right.
1. Start with the ceiling: First, paint a band three inches wide along the perimeter with an angled sash brush, then use a roller on an extension pole to cover the broad expanses. Do two coats.
2. Paint the trim, windows, and doors: Tackle crown molding first, followed by windows and their casings, then doors and their casings. If you have the space, remove doors to another work area where you can lay them flat and paint them while the rest of room is drying. Finish by painting any wall paneling or other trim.
3. Cut in and roll the walls: With much of the detail work out of the way, you can paint the walls. This is an opportunity to create a crisp border with previously painted surfaces if the line is uneven.
4. Paint baseboards last: Since you’re working with gravity, any fallen paint droplets that you missed cleaning up can be addressed now. Start by cutting in along the top of the molding, then work your way down to the floor.
Pro Tip: When painting has to be interrupted for more than an hour, Jim Clark wraps his brushes tightly in household plastic wrap rather than cleaning them. Wrapping prevents air from stiffening the paint, and the bristles are ready to go as soon as the plastic comes off. A wrapped brush even holds up overnight, though on hot days Clark takes an extra precaution: “We throw wrapped brushes in the refrigerator.” Source