Most everyone knows what blue painter's tape is (or whatever color painter's tape you prefer), but not many know how to use it effectively. There are certain steps that must be followed to get a clean finish.
Use Real Painter's Tape
Do not use masking tape or other tape that looks similar to painter's tape. Painter's tape is specifically made to be removed easily from your walls, not leave sticky residue on your walls, and not pucker that would allow paint to bleed underneath.
Blue painter's tape does not adhere well to dust and dirt. Make sure to clean the surface you are applying the tape to and ensure it is completely dry before applying the tape.
Don't Stretch It
When applying the painter's tape, do not stretch it. Stretching it causes it to pucker and not adhere well to your walls or other surface you are painting.
Try to use very long strips of painter's tape instead of several smaller strips. Every place where the tape overlaps is an opportunity for paint to go where you don't want it.
Using a bone folder, old credit card, or putty knife, push the painter's tape very hard to the surface to burnish it. You need to make sure it is 100% stuck to the surface you are painting.
Ensure no Bleeding
If you really want to be sure of no bleeding, paint the seam of the painter's tape with the color of paint underneath the tape, not the new color. Let that dry before painting the new color you desire. For example, if you have a white wall and want to paint a green stripe, apply the painters tape, paint the edge with the white wall paint, let it dry, then paint over it with green.
Two Light Coats Instead of One
When painting your wall, use 2 light coats of paint instead of 1 thicker coat that might run or drip.
When removing the painter's tape, remove it perpendicular to your painted surface very slowly so you do not disturb your paint job. Do not keep the tape stuck to the wall longer than the painter's tape you purchased recommends.
If your painter's tape does not want to come off without taking the paint with it, cut the edge between the tape and the wall with a knife using a straight edge.