this is how mine happened...
i applied in the store. a month or two later the recruiter called me. we set up an interview. my first interview was with the recruiter, trainer, and someone else..it was a 3 on 1 and very intimidating.
the 2nd interview I did the demo with the trainer
the 3rd interview was with a store's manager, but since i didn't work out for that location, i had a
4th interview with a different store manager, who hired me on the spot for a perm position
All I can say is either be, or pretend to be, very goal oriented. Mac cares most about selling, hitting their goals, and selling as many products together as possible. Many times they'll ask you to "sell" a random object to them. It doesnt matter what the object is, you need to know how to sell it. This is mac's principle rule of selling:
F - features, pick one or two features of the product and quickly go over them
A - Advantage of that feature
B - benefit of the advantage
C - complementing item to go with it
E - emotional connection to that item
here's an example of using FABCE... pretend I need to sell a Spoon
(F) This spoon is great because it's made out of Lithium, (A) which is awesome because it's one of the most light-weight metals around. (B) It's important to have something light-weight so that your arm doesnt get tired. (C) We also have this Lithium fork that pairs nicely with it. (E) I tend to always eat my morning cereal with this spoon
That was an extremely silly example, but sometimes, they'll give you the most random items to sell, so your pitch will sound equally as silly, haha. I think one time they asked me to sell a pen, and another time they asked me to sell them one of their hand held mirrors that mac keeps around the store.
I also advice to not really wear color on your eyes. It makes it look like you've tried to hard. Keep it neutral, but clean and flawless. I'd also stay away from a red or other dark lip, because mac has a specific way of teaching to apply that, and they might look for errors.
Anyway, that's all the advice I can think of for now...good luck