Recently, a lot of girls have been asking me what they should wear to a model casting. My response is always to wear something simple and clean. Your outfit should express who you are, but not cover up your body too much. When you ask me, I would recommend a nice pair of black trousers or leggings, a white crop top and of course black heels.
When it comes to your bottoms please make sure they are not too tight. During castings they will often ask you to pose in your underwear or bikini too and tight clothes can leave marks that don't look very flattering on camera. Also, for the same reason, make sure you don't wear a hair elastic on your wrist.
Your heels should be preferably black, around 10cm in hight and most importantly: comfortable. It might be a struggle to find ones that won't leave any blisters, but trust me: it's worth the investment.
However, even though I think the look I picked out for you will suit almost everybody, it's best to wear something that represents you. After all, you go to a casting to show yourself. That's why no outfit can beat the one in which you feel the most beautiful version of yourself.