1) Nothing sells your backlist like a new book. Keep coming out with more.
2) Start an author newsletter (if you don’t already have one). I recommend reading Newsletter Ninja by Tammi Labreque. The advice in there is priceless.
2b) Write a short story or novella to offer for free. I primarily build my newsletter with BookFunnel–I coughed up the $100 for a yearly mid-list author plan so I can offer Fierce Heartbreaker to readers in exchange for their email addresses. Then it’s up to me to welcome them to the list and come up with value to send them regularly (doesn’t have to be every week, but that’s what works for me).
3) Get a professional cover that fits in with the genre. Look at other bestselling covers in your category. You might have to spend $100-300. It’s well worth the investment.
4) Network with other authors–go to Facebook groups like 20BooksTo50k. Search the archives, lurk, soak up information. These are professionals and even I still find them intimidating after being in the business for 2.5 years, but I learn a ton.
5) Be consistent with social media posting and balance 80% value (fun, entertaining, engaging, informative posts) with 20% selling. You don’t have to be everywhere. Romance readers are mostly on Facebook, so that’s where I spend most of my time.
6) Always be learning. Improve your writing and marketing skills constantly–read books, take courses, hire a mentor.
I hope this is helpful!