One thing I've found interesting from past drafts are players who generate buzz in the week or two prior to the draft. After lots of analysis and film and especially workouts, there starts to be a consensus, or at least a strong minority opinion, that these late risers are NBA ready. Last year it was Shai and John Collins. And both look good.
I'd have to look up the previous year's draft to recall who was a late riser then.
Going back quite a ways, I remember that Amare had a good deal of late buzz, with one scout going so far as to say that he might be the best player in the whole class.
Again, the draft is not my specialty. And picking Top 5, the Late Riser phenomena is probably less important (unless we Trade Down!). But it seems most years the late buzz and late risers turn out pretty good.