Prior editing and proof-reading. This one is pretty obvious but also something that is often forgotten. Before publishing your work, you MUST edit and proofread your book thoroughly. Books with typos or any grammatical errors make your work seem sloppy and can easily put off a reader. The resultant negative reviews such an error would then generate could be detrimental to your business.
The power of visuals. Marketing for books need not only be done through written and spoken word. Do not hesitate to upload videos and book trailers that can market your book. People are more easily captured by visual representation of things than words so this could perhaps be the perfect way for writers to put their work in the spotlight. Make sure, however, to well market such trailers as well. Better still, use an eCommerce platform to sell your books where you are well given the option to upload such videos and better market your product.