Practice by fasteneing anything paintable, (wood scraps, wallboard scraps, etc.), forming a 90 degree to replecate a ceiling to wall joint. I like using a 2" sash brush but Im sure the pros will advise you for the best brush and technique. After patting down your brush when loading with paint, dont start your cut right at the intersection, but rather hold out about 1/4" or so away and work your way to the joint. I like to slightly twist the brush as Im working it into the joint when it meets up to it and keep a light hand. PRACTICE UP!

I don't really like angle brushes for cutting in straight lines. Seems to me that when you compress the bristles to make a fine point, you can't really do that with an angle brush. A high quality Wooster or Corona straight brush would be my choice. I like to load the brush up really well so that when you are cutting in the ceiling line you can do like 12" or so per dip. You don't really want to peck away at it in little chunks...establish your line and then run with it. Practice is of course a big part of it and so is coordination. I seriously know lots and lot of painters that can't cut a straight ceiling line to save their lives and they may have 20+ years experience painting. Another thing I do is I bypass the actual ceiling line and run my wall color up onto the ceiling by just a fraction of an inch. I do this because most ceiling lines are not straight so I need to make my own line. When it's done you cannot tell that I went up onto the ceiling but it takes some courage and confidence with the brush to go up there.

You are right about the tape and that can take practice as well. The paint line will only be as straight as the tape you lay down.

Here is a link that might be useful: cutting in video

Watched the video. Looks so easy . . .

Is that what it means when they say to paint TOWARD the wet edge?

No, keeping a wet edge is a different matter entirely, though when you are cutting in, you are cutting in towards the wet edge. It is important to always paint into an area that is still wet with paint. For example, say you were to dip and cut in a foot or so, then take a minute break and then resume your cutting in. That could be a bad move. You could end up pulling some paint off that had already started to set which may create a flash there. Flashing is like a dead spot in the paint film. Keeping a wet edge is usually most important when painting trim or rolling out walls...cutting in the perimeter of walls that will be rolled it is not so much of a problem or a concern.

I kinda do what paintguy does. I actually get the wall paint up on the ceiling when I'm painting. But then I go back and tape the walls and paint the ceiling. When I pull the tape off, it's darn near perfect. One thing you need to be sure of, is that your tape is down very well. I've used a scraper to run over the tape to do that. Good luck!

Teresa

IMO paint brushes make a BIG difference. I couldn't cut in. My ceilings were a mess. Then one day I was talking to the BM store guy. He suggested a brush.

I use Coronado 2- 2/2" brush ( the real bristles one, not the nylon). Works wonders. I can even get around light switches without removing them ;)

A poster here once said she repeated the phrase "Cool Hand Luke" over and over as she cut in the ceiling. I did that on my last two rooms, and it seemed to help me. Of course, I did have the recurring image of hard-boiled eggs to contend with. ;)

This is such a valuable forum.

I gave up using tape. Practice is the only thing that has made a difference for me. And I guess I have some natural ability...I'm good at all kinds of handicrafts, so it carries over. Even so, I usually do go back and get the blips with an artist's brush.