I go back and forth on signing actual prints. Most event stuff, I do. Most portrait stuff I don't. Just depends. I do not sign canvases at all or anything larger than 8x10.
As far as showing the proofs. I set up another appt with a viewing session for my portrait clients. Makes ALL the difference in sales $$$. For the advertising clients, I put them on the web, as it is easier that way and often they are from way outta town.