I support everything @Annabelle says above.
Also have you set up a store on Facebook and Instagram? These can link back to your website or enable transactions through the social platform.

I recommend picking a range of products and focus on a repeatable series of social posts which explain your inspiration for each, showcase your design talent, ask the audience questions about what they like about your work and lastly, try and sell the product itself.

Get your existing audience interested and engaged in your creative method first as this will make it easier to follow Annabelle’s advertising route later – you will know the “type” of person who makes a good customer.

You don’t say if you also have a newsletter but I strongly recommend this – you can then use similar messaging direct by email without having to pay to reach your audience.

Sign up to a few fashion retailers’ email newsletter and watch the frequency that they send out and what they say in each – Rose and Thorne is a good example. And start to copy their techniques.