I have had this post brewing for awhile, but reading Deadly Engagement made me finally write it.

Do: Have excerpts. I love getting sneak peeks on the upcoming books, since it whets my appertite.
Don’t: Have 200 pages of excerpts (!).  Less is more.

Do: Follow the Terms of Service. They are there for a reason.
Don’t: Obviously break the terms of service.  It looks unprofessional to find an Smashwords disclaimer in a KDP book.  ( Yes, I have found that.)

Do: Set a reasonable price, that reflect the length.
Don’t: Overprice your stories ( I.e don’t set a 2.99 price on a 15 000 words short story)

Do: Have an informative blurb ( this goes for both indies, and publishers)
Don’t:  Post spoilers in the blurb, or replace the blurb with praise for previous books.