Someone today asked me how to paint a room. About once a month, someone asks me how to paint a room because they think I'm "handy." I'm not a professional painter. I don't even like painting much. But I have gotten pretty fast at it over the years. I've ignored lots of rules and found lots of others that work. And I've made a huge number of mistakes. Even after 12 years of painting things, I still can't make my paint jobs look as good as the ones that pros do, but I can do it for less. That said, when the work requires more than 5 days of effort on my part, I look to hire it out -- pros can generally do that sort of thing in a lot less time and do it better.

A couple of rules of thumb before I start on my tips and tricks. I generally figure that a gallon of paint will cover about 200 square feet twice (two coats). I count on doing two coats of everything because I can always see through the first coat (even when the pros do it). I generally figure that I can do a 15 x 15 room in a day by myself. I use a dehumidifier to speed the paint drying. I don't paint when it's below 50 degrees, above 80 degrees, or above 60% humidity unless I have a dehumidifier, a heater, and/or an air conditioner. I listen to what the people at the paint store tell me. I don't listen to what random people at Home Depot tell me; I do listen to the ones who work in the paint department because several of them are also professional painters.

  • Pick your paint. This is about choosing material, quality, and finish. Material: oil or latex. 99% of the time I use latex. Oil is harder to work with and doesn't paint well over latex paint, but it looks great and dries hard on wood trim. Latex is easy to work with, easy to clean up, and goes over everything. Quality: choose the best quality paint you can afford; the difference between a low-end paint and a high-end paint can be $5/gallon (not much) and the difference in final product can be stunning. Here in Seattle, I use Rodda because the quality is great and the price is reasonable -- I pay under $20/gallon for the paint and the quality beats most $30/gallon paints easily. As for choosing a finish, understand that one vendor's eggshell may be more like another vendor's semigloss. In general for my work, I use only two finishes: flat (walls, ceilings, floors) and semigloss (trim and other woodwork). I've used full gloss paint once; I'm still recovering. ;-)
  • Buy primer. I prime before I paint just about everything unless I was the last person to paint it and know it doesn't need primer. A good primer (Kilz, Zinsser, or here in Seattle, Rodda) will solve a huge number of problems. If you're painting over something you didn't paint or applying oil over latex or have water spots or mold (assuming you've solved the source of those) or are just questioning the quality of the last paint job, a good primer will save you years of frustration. And remember that you can tint primer -- your paint seller should be able to tell you what color to tint it to help along your paint.
  • Expensive brushes, cheap roller covers. Unless you want your finish to look like crap, choose good brushes (I use Purdy) but use cheap roller covers. My experience is that good brushes a) don't shed b) hold their shape c) hold the paint better and d) clean up better. But I've used the most expensive Purdy roller covers and the least expensive Home Depot rollers and have seen little difference; however, I have a few tricks. First, before using a roller I wrap it in blue tape, then peel the blue tape away; this process tears off all the loose roller fluff that otherwise winds on the wall and in the paint. Second, I throw out the roller covers instead of cleaning them.  
  • Buy blue tape, lightweight Spackle (like OneTime), painter's acrylic caulk, Flotrol/Penetrol, painter's plastic, and something like Gojo or Goop. As long as you're at the store picking up your paint, your primer, your brushes, and your roller covers (assuming you have a roller and a roller tray), buy these items. You'll be happy you have them later. Especially the Goop, which is basically lanolin and cleans up paint and moisturizes your hands. You might as well pick up some latex gloves while you're at it.
  • Clear the room. Get everything out you can get out, including overhead lights, electrical plug and switch covers. If you can't get it out, move it to the center of the room.
  • Cover everything. Use cheap painter's plastic to cover the stuff left in the center of the room, and bring the painter's plastic to the edges of the floor (assuming you're not painting the floor), and tape it down to the floor. Painter's plastic is so cheap and so easy to work with that it's worth the time to cover things you're not painting. Five minutes setup saves hours cleanup in this case.
  • Fill and sand. Prep is key -- if the wall has holes, fill them. I use lightweight Spackle (OneTime) or joint compound. Once it's dry, sand it. Actually, don't just sand it, sand the whole wall. If you're really ambitious, you could apply a top coat of joint compound and sand it to make the wall really flat. Now go around with the painter's caulk and fill joins between woodwork (e.g. baseboard to wall, baseboard to baseboard) to get a nice even look. Push the caulk in with your finger and wipe it off on a cloth -- it's latex caulk, so it cleans up easily.
  • Brush off the sanding dust. How many times have I forgotten that?
  • Use blue tape, but use it wisely. Blue tape is worth its weight in gold, but I've seen people who overuse it drastically. So here are my guidelines. First, focus on taping horizontal surfaces. Remember that gravity generally pulls things down, so roller splatter will wind up on top of just about everything. I tape things like the tops of the baseboards, though I generally don't bother taping the vertical sides. I tape around window frames, but I don't do the incredibly boring job of taping windowpanes (it takes far longer to tape and remove the tape than it does to either paint correctly or to scrape off the paint from the glass). I also tape around door handles (how many times have I reached for a doorknob with a paint-covered hand) and put tape over the electrical switches and outlets (it's a real pain to clean paint out of an electrical outlet).  
  • Mix your paint and add Flotrol. If you're more than 24 hours from the paint store, open your paint and mix it. You should also add Flotrol (latex) or Penetrol (oil) to it -- these paint conditioners don't thin the paint or change its color, but they do affect how smoothly it goes on and limit brush and roller stroke evidence.
  • Ceiling-wall, ceiling-wall, trim-trim. When I'm painting a room, this is the order I do it in. Trim last.
  • Mind the cut-in. The first thing I do is cut in about 2". This makes rolling on a snap. I don't like walls covered with paintbrush strokes, so I cut in first.
  • Roll with the punches. After cut-in, you're ready to roll the walls. I use 4", 9", and 18" rollers. Most folks shouldn't try to use an 18" roller -- they're heavy and hard to handle and when you mess up, you really really mess up. But once you're ready to roll, get the roller good and wet for the first roll. If you're holding the roller in your right hand, reach up high on the left, pull down to the right diagonally, then proceed vertically right to left filling in the unpainted space outlined by your diagonal swipe. Then roll the heck out of this space to get the paint really worked into the roller cover. Remember that rollers splatter on each pull -- from top to bottom the splatter is a little less. After that, I generally do a 9" cut-in around the edge of the room, then just roll on paint as quickly as I can.
  • Plastic Wrap. If I have to stop between coats, I don't clean up. Even overnight. I wrap the paintbrush, roller, and paint tray in plastic wrap and leave them. Works every time.
  • Hold your paintbrush correctly. I've seen so many people hold their paintbrushes like a tennis racket. Some people get it basically right and hold it by the thin part of the handle like a pencil. But that will tire your hand out fast. A paintbrush should be held like a pencil, but down near the metal part by the bristles. The part of the brush that gets suddenly narrower should fit in around where the meaty part of your forefinger and thumb come together.
  • Bathtub cleanup. If you use latex paint and don't have a good laundry sink that you can mess up with paint, do all your cleanup in the bathtub. Just fill it with 2" of warm water, let everything sit for a few minutes, and clean your heart out. When you're done, turn the shower on to flush it out.

I'm sure I've forgotten something, but it seems that there's always someone out there painting a room for the first time and they all seem to have the same problems.