I look for someone who has his own transportation and lunch money, people seem to like them, and they have a basic understanding of the process. They take care of themselves and people's property. If they already know it all, it usually doesn't work out too well. If they don't know what NOT to say to a client, it usually doesn't work out too well.
People skills, a willingness to do whatever it takes to get the job done, even if that means taking out trash (if you don't do it, I do, so stop complaining), cleaning, fixing, etc. I don't need someone who can mix already, just an honest, ready to work helper that knows enough to be helpful, but not so much that I have to un-train him. You gotta wanna work. Gotta show up early and stay late. Make yourself indispensible, and you will be hired out of necessity.
It seems every up and coming engineer I train to work with me ends up getting a pretty good job somewhere, and I have to start over with someone else!! It's fun!