Your best bet is "word of mouth". Also, create a blog and Instagram account to showcase your talents. You can get friends and family to model your wears for you for free. The blog should talk about hats, styles of hats, etc. while still maintaining some focus on your products.
My company is called kofia hats and are knit hats that are really nice and comfortable and I sell them in my school but I'm looking to sell more of them. Any websites to sell them?