Utilize existing memberships
You can improve your SEO rankings by creating quality content and building relationships with other webmasters.
If you are cold-emailing for guest postings on like-minded sites, then it might be worth reaching out via social media or a blog post.
These strategies aren’t novel or new, but they work. Try not to do it all at once. You should start with one and learn from it. Then, you can improve your approach and continue to build. You can reach me on Twitter with any questions.
Google's #1 goal (and every search engine for that matter) to deliver relevant results is to answer the query. Users don't want to search for "shoes available for sale" only to find tons of tennis rackets.