If you want more free traffic from Facebook then the best way to do this is to increase the amount of engagement that you get with your posts. Engagement is an action that a Facebook user takes with respect to your posts.
The most popular forms of engagement are commenting, liking your posts, and sharing them but engagement can take other forms such as clicking links and tagging you in other posts. All of this engagement helps you to improve your organic reach.
When your posts have a lot of engagement this will help to get them increased exposure in the news feeds of your audience. Getting more shares and likes will help you to reach the extended network of your audience.