1.How you can promote your online boutique for free you can tell friends and family
When approaching family and friends you can create an event with samples of your merchandise and have a little get together explaining
your online store. Make sure you keep the day that you are doing the event.
2. Another way you can promote your online boutique free is Social media
(create a fan page on Facebook.)
post in Facebook groups with related interests.
Tweet about it on twitter
Post videos and of real people wearing your merchandise on instagram. Include your boutique link in your bio. Do the same for vine.
YouTube create a good quality youtube video with someone or even you modeling the merchandise you are selling. Don't for get to post your link in video and /or description under the video with a contact email address if people have any questions.
these are the effective ways I know that will drive sales to your boutique online.
3.Create a blog filled with images of the merchandise you are selling.
4.To Also promote your online boutique business you can Collaborate with Fashion blogger or even instagrammers and youtubers to promote your brand in exchange for free products.
In the meantime I hope this help you out start your own store boutique http://fashionsuicide.kitsylane.com