This old PaintSource Network video does show a great technique for masking baseboards, trim , and ceiling before painting walls for a better quality paint job. Easy to follow instruction.

UPDATE 2024:

Frog Tape Green should be used for baseboards and where we use green tape in this old video. Frog Tape Yellow should be used for ceilings and most vertical trim. Yellow frog tape is superior to the Purple Delicate surface tape demonstrated in this video from 2008.

https://paintsource.net/