To increase blog traffic organically, SEO optimization is the best technique to follow. Find high search volume Focus Keywords, good Title and structurize the body of the blog by providing heading, sub-heading, H1 Tags and user-friendly slug.
Tools to find Keyword Volume: Google Keyword Planner
Best SEO Plugins for WordPress blogs are:
SEO Yoast: https://wordpress.org/plugins/wordpress-seo/
All in One SEO Pack: https://wordpress.org/plugins/all-in-one-seo-pack/