I was trawling about the interweb thingy today for some concise info on setting up a fretless neck and came upon this site which deals with the Gary Willis Ibanez, but can be applied to others as well.
http://garywillis.com/pages/bass/bassma ... anual.html
Fretless Neck Set Up
“I venture not to cross that finish line in a neat, tidy well ordered bundle, but to slide across it sideways in a shower of spark’s, leaking oil, hissing steam shouting ..Geronimo !!!!! “