In my discussions with customers, most do not know the difference between authenic crown moulding and molding on the wall up next to the ceiling, like base molding. They think that they are the same.
Base board molding on the wall, nested to the ceiling looks better than no molding at all, but nothing like the asthetics of real crown.
Real crown or the only crown is joining the ceiling and the wall with molding that is angled one each end to fit at that angle on the wall and ceiling together. The joints both inside and outside are ones that will drive you up the wall. One angle you do upside down and backwards and the other becomes its mate.
Then you Must have a compound electric mitre box saw. the key is compound. Some people around still do the coping method and I personally have not had any luck with that.
So, to keep your sanity and your love for each other, hire a professional that does crown to do yours. then watch him/her carefully and you can "pirate" the work.