1) Never pay for reviews (this does not include review companies such as Netgalley, Hiddengems, OnlineBookClub, etc. which charge to list your books on their sites for their clients to voluntarily choose to review if they want.)
2) Look at the book covers of the top books in your genre. Does yours compete?
3) Don't do your book covers yourself unless you have experience in graphic art.
4) Get input from other authors on your blurbs. Some authors find them easy to do, while most do not. Avoid outlining the entire book--explain the first 1/3 of the book and use a question to make the reader guess what might happen in the last 2/3.
5) Do not harrass other authors to read/reveiw your book or do review swaps. Most authors do not have time for this and the popular authors are constantly being asked to review other authors' books.
7) There are over 1000 groups on Amazon that will let you promote your books in them. Do a search for your genre or "book promo" and you'll get tons of them popping up. Read each group's guidlines for posting so you don't get kicked out.
8) There are numerous groups on Facebook that are for authors only, to develop their craft and with tips on how to market. Join them.
9) Set a monthly budget.
10) Research the different book promotion sites and ask other authors about their experiences with them.
11) Don't put your book on sale shortly after a release because your sales are down. Readers get upset when they see a book that just came out, that they already bought, going on sale within the first three months of release.
12) Don't overprice or underprice your book.
(Yup, more than 5 but all needed to be said!)
1) Don't give up.
2) Listen to the advice of authors who have come before you, yet do what works best for you.
3) Get an editor.
4) Read other authors in the top 100 of your genre to better understand what readers like.
5) Never respond to reviews, but take a bad review and use it as constructive criticism to make your books better.
6) Leave your ego at the door
(Okay, that was six, but they are all important.)