I have installed crown molding in all of my bedrooms and at first I used a tape and made my initial cut 1/2" long to be safe. In the last bedroom I got a little more sophisticated and used pinch sticks although it wasn't perfect because I just clamped them to length and often the clamp slipped. Now I have to make some long runs and some of them are on an 18' high ceiling. Any tips on getting an accurate measurement between walls? I always cope which allows some small error but I'd like to keep my trips up and down the scaffold to a minimum.