I find myself coming back to Hazel every so often, and geeking out trying to make it do even more than I had been previously. Sometimes it takes a while for the power of Hazel to "sink in", and other times it's just a matter of deciphering the proper rule logic to make everything work properly.
I had been wishing for some sort of "best practices" page or thread to help me wrap myhead around some of the rules and actions in Hazel. Since I never found one, I thought I would start it myself
(I suggest each user that posts a "best practices" tip here makes sure to edit the subject line of their reply so we can easily sort out and find these individually.)
I'll start things off with a reply (below).