Painting straight lines on textured walls?/

[DD716TED]

I am painting a room where two textured walls and a textured ceiling meet.. I want the ceiling and one wall to remain white while adding a color coating to the adjoining wall.. One person tells me to use Frog Tape, one person says to use blue tape with paintable caulk applied and the local paint store is suggesting that I do it with a fine brush (freehand).. From your experience, what is the best / easiest way to do this project??

[pushkins]

I'm a laser line and free hand guy, I'm not a fan of any of the tapes.
A caulk line is a good idea but you have to be exact with the caulk line hence the laser line.