Haha, yeah tape off the door knobs? Take those off for professional results. If you want to brush your doors, you should roll them anyway and then back brush them. The rolling gives you a method to get the paint on the door quicker. You could also just roll them and leave them be as well. That depends on the look that you prefer. It also may depend on the paint...some paints don't dry down nice enough to be rolled and left.

These little rollers caught my eye on HGTV. I'd never seen anything like them before. I saw them in HS yesterday. Very inexpensive and apparently quite good for very smooth surfaces. Less mess to clean up, too!

If you are using acrylic paint, it's very hard if not impossible to brush out a door, or any large surface, and have it come out looking good. You should either roll the door and leave it or roll the door and brush out the rolled paint. Modern day paints just dry too fast. Aura is a good product for rolling and the Aura extender you can buy to increase the open time is also good. Regal is not really a good product for rolling...it does not self level as good as the Aura. Also, this does take practice. DIY'ers and homeowner painters have 2 tendencies. They do not put enough paint on and they overwork the paint. The key to getting paint to look good is to put the paint on heavy and then leave it. After 15 second have passed, do not go back into an area that you have already painted. Try a 4" Wooster Pro Dooz sleeve, 3/8" nap or even 1/4" if you are afraid that 3/8" is too big. The pros always tend to use bigger naps than the homeowners. Try not to get frustrated...painting these days is hard! This is why I try to spray as much as I can.

We experimented with our wood paneling and found that a SW 6" blue knit 1/2" nap SW roller worked best for us. Using that roller, we did not have to play with the grooves, they filled right in. Sure you may have to push a little harder on the groove part, but you will have equal consistency everywhere. This was a small room and we did it in sections, so the small roller worked fine around windows, doors and trim. A larger room you may want to go with a larger roller........we were in no hurry. Quality was more important to us. One coat of primer and two top coats of Advance. We could have brushed it on, but brushing a wall just takes more time and doesn't seem to be quite as even. When we brushed the grooves first, we saw the outline of the brushed grooves when the paint dried. So the final coat we just rolled the whole wall and it looked even. ...very nice job!