I'm having trouble working out how to finish off the ends of the crown moulding (not installed yet) where it meets the stairs. It will be quite a wide moulding so I'm thinking some sort of decorative end piece if they exist. The real problem spot is where the wall goes right up to the stairs but the ceiling doesn't, do run the moulding up to the stairs too or stop it where the ceiling is & leave a gap?

Any suggestions? Thanks