Of course, the question is what do you paint first, after all other work is done and everything is cleaned up and dust removed. The obvious answer is that you begin by painting that which is higher and which can drip down, such as the ceiling. The trouble is that obvious answers are not always right.
It all depends on your plans for the trim. If you're going to be painting your trim (with latex or oil-base paint), then the proper order is as follows:
When Painting Trim
1. Paint ceiling
2. Paint walls
3. Paint doors and windows
4. Paint trims around doors, windows, and baseboards.
If, however, you're going to be staining your trim, then a different plan of action is in order. It looks like this:
When Staining Trim
1. Stain all trim, preferably before installing it. Use sanding sealer to raise the grain; then sand and varnish the trim.
2. If trim is already in place, stain as above, allow the stain to dry, and mask the trim.
3. Paint ceiling
4. Paint walls
5. Paint doors and windows
6. When all the paint is dry, either put in trim or remove masking from existing trim and touch up as necessary.
Remember that, if you get paint on the trim, you will have to sand it carefully-a tedious job-before you can restain it. Therefore, you want to do the painting and the staining separately.
What's the Proper Procedure for Painting Doors and Windows?
For doors, start at a top corner and work your way across and down. Use a brush and be sure that you work quickly to avoid having the paint dry. It's much harder to paint a glossy acrylic latex on a door than a glossy oil paint.
Beware of backpainting a door with acrylic latex. This common practice involves painting the entire door with a roller, then using a brush to smooth out the paint and give it "brush marks." The problem is that acrylic latex dries quickly and without you work fast, the bottom of the door (the last place you'll be working) will be dry before you get to it, leaving brush or roller marks.
For windows, particularly French windows (with lots of small panes of glass), painting can be a real hassle. You'll need to use a small (1-inch) trim brush for the dividers. You can try masking the glass, but that will take longer than the actual painting. Instead, use a plastic putty knife, found in paint stores, as a shield. Hold it against the surface you are painting to keep the paint away from the glass.
If you use a shield, you'll have to clean it off with a rag after each use, else some paint will get behind it and onto subsequent panes. Usually a little paint will not hurt. You can clean it off quickly with a rag, or come back later on and remove it with a razor blade. Beware of window glass that has a rough surface. It will be almost impossible to remove any drawn paint from the glass.
Wear eye protection when painting. Getting a drop of paint in the eye, particularly oil-base paint, can be very painful and could damage the eye.