If you do not order fashion style designer, then take a lot of clothes with you. The more dresses, clothes, shoes, accessories you take with you, the better! Ideally, I would like to see your whole wardrobe. Clothes are very important for photography. Also, changing clothes in the course of photography creates more fun and motion to the photosession, which is important to obtain best result.
If you are a lady, please note that trousers and bras do not look good for photography. Ladies look best in skirts or dresses. As the last resort, you may consider jeans or shorts. For the open air photography, sundresses may fit you.
Please, avoid shirts with inscriptions, such as I LOVE NEW YORK. They look terrible on photos except for very special occasions.
Should you have any hesitations/questions in this regard, please consult with me.
Please remember that there are professional fashion stylists who used to dress famous Ukrainian stars. I would recommend you to use their services.