This is how an inside corner looks, for example. You will most likely have to cope the molding to get it perfect like this. And I have no idea how to do it. I've looked it up a trillion times, and can't figure it out.
Soooo...what's a girl to do when she LOVES crown molding and has no patience, and isn't going to pay someone a ridiculous amount of money to do it for her? She finds these fun little tricks: inside and outside corner pieces. Yahoo!!
These little corner pieces are awesome. You paint them and nail them up in the corners, then just place your molding up against them. Turns out I love the way they look too. They add an extra elegance to the room. The smaller pieces for regular-sized molding are only a few dollars each. They get more expensive for the thicker molding but are still not that bad. Especially considering the alternative -- not doing it at all or paying someone to do it!!