Any good way to tell a faculty candidate "We don't want you"?
Getting a rejection sucks. There is not much you can do about it. My wife and I have talked about this a lot and as candidates the only thing we wanted to know was how close we were and how we stacked up against the people who beat us. When sitting on search committess we have had various levels of success trying to inform candidates in the rejection letter about how many applicants, how many first round interviews, how many campus visits, how many offers, and was the position filled.

The other thing we do is make sure the letter starts off with we cannot offer you a position and then includes all the other information.