For me, I have to do extra training now so I pretty much let them watch the entire process first, then I will have them come back and do it all themselves while another one of my aides is watching and helping when needed. Then, I finally let them try on their own and I will try to be very patient and slow and forgiving.
One of the best pieces of advice I ever heard is to allow the first day or 2 with them to be pretty far from perfect, like if the shirt is really sideways or if certain other details are totally off (that aren’t critical). That way we can focus on just getting through it and then working on the particular details the next few times they come.
I also like to do a little theft test as well for new strangers, like leaving a $10 bill laying around somewhere visible just to see if it disappears in the first few days or weeks.
I can usually figure out by shift 2 if it is going to be worth the effort to continue with this person, which reminds me you may want to consider letting them know that the first 2 weeks are a trial period that either of you guys can decide for whatever reason that it isn’t a good idea to continue, and that the person doesn’t even need to let the other know why. Presenting the idea to them like that may help you see how agreeable they are going to be working with you in the future.