In my opinion, the keys to being overrated are:
1) Be on an NBA championship team. How often have we heard about some benchwarmer that "he has a ring," as if that makes him good? .
2) Be a top scorer, but without having a high shooting %. Ppg is the one stat everyone knows. It's the shortest shorthand for value.
3) Be a mediocre or worse defender, because casual observers don't care about or can't evaluate D.
4) Be an NCAA champion (preferably the star of the team) because you will always be famous and a "winner."
5) Be part of a famous draft class so that you and the others in that group are always considered somehow equal (except the "Darko" of the group-- although David Kahn is still falling for that).
6) Have underrated role-playing teammates: good rebounders, high TO-to-assist ratio guys, low frequency 60% shooters. The public doesn't value these guys, and will attribute any successes to you.
As evidence: there's one NBA player who meets five of these criteria (none who meet all six). He is regularly called a "top 5" or "top 10" player, yet using any overall stat to measure his value comes in at about 30th. None of the other most-cited "top 10" guys is anywhere near that low. Can you guess who this man is?