From your post I think you mean in flight
I just look at them and only use two positions full down or full up. As I approach the airport I start slowing to flap speed. If I'm on base or downwind etc., and I'm not at the top of the white arc I pull up the nose enough to slow appropriately and hold the switch down untill the flaps stop moving then I trim and make adjustments with slips or power to set up for a good landing. I do not use any intermediate flap settings and saw no reason to in the 7 years I been flying our RV-6A. Your Rv-8 may be different but I sorta doubt it.
Afterthought: If you are talking about rigging, I leveled the airplane canopy deck plane ref the Earth then uses an inclinometer (sp?) to check the flaps and control surfaces to assure the minimum range requirements were met. Initially they were not and some adjustments were required.
Bob Axsom