There are a few techniques out there (and all of them requiring practice), but here is how I do it:
1. With a loaded (angled) brush, swipe a paint streak about a half an inch below the line you’re about to make. It’s important that the paint in this spot be wet but not drippy (you’ll see why in a sec).
2. Now that you’ve unloaded most of the paint onto the wall, use this as a place to basically pick up paint and drag to the line you’re going to create.
3. By keeping the brush smushed and half-loaded with paint, a line is actually pretty easy to create. When the line gets streaky, just move the brush down to the stripe to load more paint onto the brush, and continue on.
4. Of course, all you’re concerned with really is getting the straight line. When you’re done, it’s likely your straight line will also be streaky.
5. One more swipe of a loaded paint brush, and you’ll have both a straight and solid line.
There you have it. It may take a steady hand and a little time to concentrate, but it will save you plenty of time (and money) in the long run when you don’t have to tape every baseboard, windowsill, and doorway. Plus, the pride of knowing you’re painting skills are pro quality is great, too!