I completely agree with @Jason that building a brand will help you increase organic traffic. Also, use only quality content on your website and build quality backlinks. It will surely help in increasing your organic traffic.
Social Engagement. You can use social media to promote your website in order to get more traffic. You can also advertise your website on social websites like Facebook. Similarly, engaging customers on social websites bring traffic to your website.
In my opinion the best way to increase organic traffic is to optimise for your readers not search engine.
Nowadays millions of people have access to internet, so you can use social media to attract organic traffic.