+1 on that!
I don't bother with interviews anymore. 5 minutes on the phone is enough to sort the ones who have actually done tree work from the ones who are outright lying just to get their foot in the door. Simple questions like "who did you work for, what kind of chipper did they run, what sort of saws did you guys use' etc very quickly lets you know if they have actually done any work. If I know the company they used to work for (it's a small world!) I might call the guy up and ask, but probably not. I'm not so fussed about appearance or attitude, there aren't that many good workers out there so I'm willing to cut them some slack if they've got long hair, piercings etc. In an ideal world they're clean cut, straight laced and not an alcholic or on drugs, but lets face it; this industry doesn't pay enough to attract and retain high quality groundies.
If they sound ok, I give them a days work. I don't put people on the spot, we just get working. Run them through our short chipper induction and they get to work. The other boys keep an eye on them. During the day sometime, if he seems to drag and chip alright, one of the boys will hand him a saw without any real instruction. Some time later someone will hand him the lowering rope. I don't give specific instruction to guys on the first day, just watch them to see what they know and what they're made of. By the end of the day you know. If they did alright I put them on for a month with review. Not that many guys last till the end of the month anyhow.
Shaun