(written for some other writers looking for ideas on how to do stuff. Sort of a brain-dump, so don’t expect great flow and organization, and this is a paraphrase of events)
What I did: I had ideas for a story. I started to put them together. Once they were done-enough, I contacted a friend of mine who had a blog with something like a thousand regular readers who were generally of a mindset they’d appreciate the themes and characters of the book. I arranged to post it as a series of small daily installments. The purpose was both to get feedback and build an audience. When I was nearly done posting the story, I wrapped it up with an editor* and cover art, self-published on Amazon, then told the blog readers that it was out and provided a link. About this time I also launched my own blog/website**.
The blog with a thousand regular readers turned into about a hundred regular readers of my story, which translated into something a bit more than a hundred purchases of my book in the first week it was on Amazon. Sales rank is determined by sales velocity (volume per time, with some sort of algo they don’t share). Selling enough fast enough to get into the top hundred of your genre is critical, because it being listed in that “currently hot titles” will market it to regular readers of that genre that you never met, don’t know, etc. I also had begged and pleaded with some of my beta-readers to make sure they posted a review very soon after buying it (after all, they’d been reading it as I was writing and blog-posting it in episodes), so that the new people who’d never heard of me before would see the title, see it was new, see a handful of reviews, and take a chance, pushing it further up the rankings. That becomes a virtuous cycle.
If I had to do it over again, I’d have broken my book up into two or three volumes, then when one was doing well but had peaked, and starting to fall back down (maybe a month after the first one) I’d announce and set a near-future release date for volume two, so that the people who liked the first one had a chance to jump on the second one and push it up the sales ranks n the power of Amazon’s algo and their regular readers. Then repeat it a month later with volume three, all the while furiously working on vol 4.
At this time, I also was a somewhat regular reader of several large blogs, and a somewhat regular poster in their comments sections. My story would appeal to a portion of the regular readers there, so I made a small plug in the comments sections of those websites. I also found some blogs that would post regular indie-writer plugs for new books. For example, AceOfSpadesHQ has a regular weekend book thread. I sent them a short writeup, and plugged myself in the comments a time or two, around the time of release, so that it added a bit to the sales velocity. Coordinating them would be ideal, but you don’t want to blow it all and have all your sales in six hours, then nothing for a week. You want a surge from plugs and posts to cause enough sustained sales for a week or more that regular top-100-list browsers will get a chance to see it. There are web-sites and articles that talk about how this works in more detail.
Now, the unique part to me was that after I’d guerilla-marketed my way to selling about a thousand copies, I accidentally got a publisher, because Vox Day was just starting up Castalia House and was looking for writers. I won’t bore you with the details unless you are really curious, but long story short, we worked out a deal for “The Stars Came Back,” a short story in “Riding The Red Horse,” and later they also published “The Heretics of St. Possenti,” but then I went back to indie self-publish for “Insanity’s Children” and “Komenagen: Slog.” the former stuff got me nominated for the Campbell Award, but that was part of the Rabid Puppies episode of the Hugo Awards and GamerGate extravaganza.
Jumping genre is not something I’d recommend. I did, sort of, and it worked after a fashion, but I’d have made a lot more money sticking to one genre series first. My corner of the world is weird, and my first three book were all part of the same universe / series, but totally different genres. Cover art is tricky, do some research, and usually consulting someone who does graphic design for book covers will give better advise than an artist. They are closely related, but very different skills. Great art might make a bad cover for a particular book. Make sure you know your target audience, and aim your writing and art for the genre and audience. Write snippits and post regularly, preferably daily, so your regular readers come to your site on a regular basis.
*editor: Yes, you need an editor. Beta readers are great, but a good editor is invaluable. Really. You do. Get one.
**Note: give your blog a generic name, not your own (you might sell the franchise) or the name of your book ( you might come up with a more successful series later).