How did you get hired? What did you do? I'm really interested in working at one as I love looking at glass, but am not sure about the protocol.. I feel like going in in fancy clothes would not go over well, but i wouldn't wanna dress like a bum asking for a job either. I know a decent bit about glass but would obviously teach myself more before attempting this.
Probably helps to know some people who know some people who know some people who know some people AKA Having a network.
most headshops (atleast around me) are small were the owner works there and usually personally knows most of his employees.
My city has 2 headshops, at the one I usually go to the main employee is always wearing a crazy dress, at the other it's a bunch of hipsters. Personally, I'd go the hipster route.
I would dress in what you wear everyday, but make sure you look presentable and smell okay. Dont be testing out any of the merchandise either, that's a good way to get fired
I used to work at one.. now I blow glass for a living.. You just need to get to know the employees. and put in your resume multiple times.. It may be a headshop but they still like people to be professional about asking for a job.. the more you hang around/get cool with the employees.. the more likely they are to recommend you to the boss when your name comes up for a job. good luck!