Proper Ventilation When Painting

Hello... I am trying to get a clean line (edge) painting on an orange-peel textured wall. I'm painting an office that has an arched doorway. The %!$#@ paint bleeds through even though I pressed very hard on the blue tape prior to painting. When I removed the tape, the line looked terrible. I read where you can apply a clear glaze or caulk on the edge of the tape, but I don't understand this because it seems to me that you would have to get the glaze or the caulk to be a straight line because the paint would butt up the the caulk or glaze and if the caulk/glaze isn't straight, then the paint won't be either. What am I missing here?? I also saw this: [[Tape off the inside of the line Paint your inside color up to and on top of the tape Let it dry and then peel the tape Tape off the outside of the line, right on top of the first paint line Paint the inside color over the top of the outside of this tape line. This will fill in the gaps under the tape from the texture. The gaps will now be filled with the inside color. Lay it one thick to make sure you fill up all the gaps. Paint the outside color over the paint you just laid down Peel the tape ]] ... and I don't understand this the way it's explained. Can someone PLEASE explain a way to accomplish this to a painting amateur? Thank you very much! Eric

I painted my living room red and the black crown molding white: and thanks to the advise received at this forum the result was FABULOUS. I'm so glad I checked in here and asked, even though my questions seemed dumb to me. Now next, the bathroom. There is a red wall in there, that needs to go. They have painted this room in regular paint, and the walls are filled with streaks. Any particular advise on this project? Is there a specific primer for bathrooms? Just thought I should ask, because I shudder to think what my LR would have turned out like if I hadn't had the courage to come here, and the advise from the paint store wasn't nearly as helpful as on this forum. Again, my gratitude............Shirley