So we bought this house, an HOA neighborhood only about 25 yrs old. TERRIBLE builders in my opinion. As I'm installing baseboars, chair rail and just starting crown molding, I've experienced some really poor measurements in ceiling to floor areas, floor to chair rail un levelness, walls that are supposed to be 90 degrees aren't, and so my 45 degree cuts are off in a bunch of spots, etc. I'm a new DIY, and dealing with it.
So now I'm starting Crown molding and my first piece right off the bat, I'm getting hit with a middle down bow in the ceiling, leaving a 3/8's " gap on each end of the molding. I've gone through and looked at other areas now like the living room, etc and see a few uneven downward dips. I'm guessing between studs?? here and there. What does a pro do in this case. How do I avoid looking like I fastened a snake molding up there, AND having huge gaps to fill in?