1) 99 CENT / PENCE MILLIONAIRE.
Most authors have heard of this phenomenon: the 99 cent millionaire. Basically, if you price your book at 3 or 4 dollars, you have a chance of selling okay, given the cover, blurb, and content are good, and a marketing plan is in place. But, if you price your book at 99 cents / pence, you'll likely sell more, which means more individual readers, more reviews, and a larger outreach. I know what you're thinking, what about the money? Well, if you sell a few more copies at 99 cents the profit will balance out, if not work out for the better. As an author as well as an editor/marketer/formatter, I have found that my books sell greater when priced at 99 cents / pence. You actually make more money than if you priced it higher. And as already said, you are reaching more readers - which is what you want to do - but getting the same (or more) profit.
Never miss out on an upsell. Have banners on your site for your books. Have teasers at the end of your books, advertising your other releases. You get the idea. This will create a snowball effect and have readers going from one of your books, to another, and another.
3) HAVE A PROFESSIONAL LOOKING WEBSITE.
You may think readers won't visit your site. This would be a grave mistake. They may be interested in your other releases, or grabbing a freebie, as many authors offer a free incentive to sign up to their newsletter. Not forgetting, you should mention your website at the back of every book, enticing them to go and check it out. So, why would you have a shabby site? Make it professional. If you don't know how, find help.
4) HAVE A SOCIAL MEDIA PRESENCE.
We all have our preferred sites, whether it be Twitter, Pinterest, FB, Instagram etc. But it's better to have an account with every social networking site out there. You don't wanna miss out on readers. It may seem overwhelming, but once it's done it's done. You can copy and paste the same info from each. This will just help you reach more readers.
5) FOCUS ON GETTING REVIEWS.
We all know the importance of reviews. Lots of reviews will sway readers to grab a copy. You want a mixture of good and bad (yes bad) reviews to add legitimacy to the book. Contact bloggers, look on Goodreads, ask friends and family, find reviewer websites. This requires effort if you are serious about your author career.
Good luck from Thomas Author Services!