Influencer marketing. Find a bunch of micro influencers with sub 5,000 follower counts on twitter, insta, fb, snapchat and offer to send them free product. Maybe throw in a referral link and pitch them on the commissions they can make.

The price being only your time to find them, communicate with them, your COGs, and shipping.

Over time it can have a compounding effect on growing your brand while also driving immediate traffic to your site.