The thing I hate the most about painting is the prep work. I absolutely hate taping the edges of a room. It's the painting I love to do. The Dude is the opposite. He doesn't mind taping, but he hates painting. How could you hate the most fun part?! So I make him do all the taping.
Anyway, I searched on youtube for painting without tape methods and found the "cutting a paint line" technique. I looked at several videos and turns out there are slight variations for this particular method. This was the one I liked the best:
I used this method to paint the bedroom, and it has revolutionized the way I paint. After a few tries, I got the hang of it. Vibrating the brush a bit while I cut a line seemed to work best for me. I also held my breath when I first began, but after a while I could cut a line while breathing normally.
Also, the secret to cutting a straight paint line is to use a damn good paintbrush that's angled. I splurged on a good one by Purdy that's 2 inches wide. And it's crucial to load the brush with the right amount of paint or you'll end up with a mess.
Using tape has it downsides: it's wasteful, it's a pain in the ass to put up and take down, and the paint usually bleeds through. Drawing a paint line by hand is a win-win...except for when you mess up. But paint is easy to clean up when it's wet. So just wipe off and start again.