For me, I am luckier than most in that I have been touring for 45 years now and have over 70k loaded touring miles. The biggest criteria for me is riding somewhere I have not been before. It can be the same state but with few exceptions but I prefer not to do the same routes/roads as before as I like to see new stuff. The next is scenery, then weather (temps then wind), then difficulty. Most logistics work themselves out one way or another if fully self-contained but I do prefer a shower every night if possible. Good question.
Tailwinds, John