Having just got her first interview for Uni DD1 is now worrying about what to wear ! She has to wear business wear for school so has a trouser suit and skirt/jacket if needs to be formal but is casual more usual ? She will be mortified if she gets it wrong
I wore a skirt and jumper to mine I think (not tiny denim skirt, but above the knee. So smart-ish but not too old/formal looking.). I think to one I might have worn dark skinny trousers tucked into knee-high boots and a jumper.
They're more interested in you as a person than what you're wearing, but obviously you want to look presentable!
(God, that sounded like we care what students wear to interview - actually, we don't. It's the mind that counts, nothing else. But we all know that subconsciously clothes can sway people, and why risk it?)
My DD did MFL and got offers from Southampton, Bath, Warwick, Durham & Cambridge. She wore a skirt & blouse to her interviews - Not a suit skirt but a smartish one, and quite a fancy blouse (I would have gone for more formal) - but is was what she was comfortable in. Her 6th form did not have a uniform.
DS wore his school suit because that is what he was used to, but both saw lots in Jeans as well as high fashion.
Thing is, as an academic, I suspect if I'm swayed at all by what applicants are wearing (such influence would be utterly minimal, I hope!) I'd be more put off by high fashion/too smart, than jeans and a tshirt.