Getting free/organic Facebook traffic is the best way to do it, since it means users are genuinely fans of your business, and more likely to become long term supporters.
Getting more natural traffic is all about posting good content. Take good photos, write clever captions, shoot short videos. If you think your posts are high enough quality but still not getting traction, find relevant Facebook groups or niche subreddits to post them in.
For example, if you sell handcrafted sofa covers made of hemp, find hemp fangroups to post it in. This becomes a win-win situation. The group gets an exciting new topic to discuss, and you get free advertising.
Also, trial and error will go a long way. Constantly try out new content ideas, and find new groups/forums/websites to share them.