This dining room had a tray ceiling that was painted the same color as the walls. The homeowner wanted the ceiling to really stand out, so we painted it white and installed crown molding in the tray, and base plus crown molding around the edge. The base molding went under the crown to build it up and make it look even more significant.
We started by painting the ceiling (you really don’t have to cut in if you are installing crown molding all the way around). The light fixture came down too as the homeowner had one that was to be installed when everything was completed.
I cut and coped each corner as I think it gives the best fit you can get with either base or crown molding. Trying to cut crown so that it just 45 degree butts into eachother will never give you a great finish. The walls (especially where the walls meet eachother or the ceiling is never truly square). Drywall and plaster have the same problem- the corners are finished with a trowel or taping knife and are almost impossible to get perfect.
Here is the finished product with both courses of crown molding done. The one around the edge also has the base molding under it. Once it is up and caulked and painted, it looks great, and really sets the ceiling apart!