|Keep It Simple, Stupid|
I hope you're looking for the criteria used by some of our colleagues... and hope you've read What is moderation? and (especially) How do I moderate? which says, inter alia, " It is good practice to front-page only nodes which are well written and well formatted, will not take up too much space on the front page, and contain information relevant to the Front Page audience — namely, visitors and newbies." *1
The real meat occurs a couple para further down under the head "Front-Paging a Node and in the following link, What nodes should/should not be FrontPaged? (and, in turn, Considering Front Paging a Node?).
Nuff' said? Well, here's a Readers' Digest version of my criteria: Front page, if and only if, the OP is a concise, well-formatted question which is clear and not a FAQ, and deserving (IMO) of an upvote! Be stingy with FPs when the site is busy -- generally, M-F -- and less so on holidays and weekends.
Most of what's beyond that is mere elaboration... and, FTR, I don't think I've ever FPed a thread solely on the basis of excellent answers. My theory is that visitors or newbies scanning the Front Page select what to read based on the question.
*1 Update: Let it be noted, some of the content cited later disagrees with the quoted characterization of the folk reading the FP.
Questions containing the words "doesn't work" (or their moral equivalent) will usually get a downvote from me unless accompanied by: