One thing I've gotten into the habit of doing is looking around the commit history and issue list for any package I import. Was it something somebody wrote in a hurry and hasn't really touched since? Is it something that has a solid set of regular contributors? Are there a lot of outstanding issues relative to how heavily used it is?

I also spend more time actually reading through specs to see how well they exercise the code.

That's probably standard procedure for a lot of people, but it's something that I had to learn to always do.