I go for a breathable short-sleeve shirt and the new Degree deodorant- even short sleeved, your armpit might get on the gent's long-sleeved (if he's wearing one) shirt, and I found out the hard way- the wrong deodorant will actually turn a black jacket purple. Get the good stuff from Degree.
I don't know what No-Name's thinking about the jeans. Reasons why jeans could be unacceptable: People "abuse and misuse" jeans. They wear them to funerals and weddings, nice clubs, etc. when jeans really shouldn't be worn, but rather trousers or a skirt instead. If it's a comfortable, laid-back studio (like ours), jeans would be fine.
Jeans might be "unacceptable" because many jeans just don't stretch or give, and they can be very hot. Gloria Vanderbilt Jeans are nice, stretchy jeans (sorry, I refuse to wear hiphuggers until... hmm... maybe next summer. I should be ready for them by then!), and they don't "sweat ya". Lots of comfortable give, and they're nice-looking, too. There are different shades of them, too. I have a lighter pair and a darker pair.
Other than that, don't listen to 'em.
I agree, though, either wear athletic wear (Adidas makes some really neat capris now) because it's actually suited FOR the job, or something breathable, movable, comfortable.
On your shoes- just make sure they don't "flop off your heels". If you have to, get straps, or I can show you how to, in a pinch, rig Rubber bands on 'em, BWAHAHA (yes- they DO look VERY VERY DORKY that way, but sometimes, desperate measures are in order!)