Best thing: No need to watch over them!
I have been working with Harrer Electric Ltd. on and off for about twelve years now. I use them for residential construction. They take instruction really well, and the best point I can make about them is that I don't have to watch over them. I let them know what I need done, and they get it done right away. I don't ever have to worry about them. They're very good at dealing with difficult situations, and they're also really nice guys to work with. It has been great.
As long as you give these guys clear instruction, they will perform well for you.