I know the tip to use a q-tip or makeup applicator to get in the tight inside corners. I'm asking more about tips on not bumping into the adjoining "wall". Like when painting a room, you're supposed to cut in a new wall (wall B) - not getting any paint on the adjoining wall B because you will get a line on the adjoining wall B because you'll have one small line painted before you go back and pain the rest of wall B after wall A.
So if I'm using a rag to stain, any tips on how to get close enough to the edge that is filled in with a q-tip, without getting stain on the adjoining wall. I might be too lazy to tape off the other sides.
Thanks