In Amazon terms, a hot new release is better than a best seller, the latter in the UK requiring one sale (depending on the category). A hot new release needs about 10 or so sales. Of course, when e books stop being new, they stop being hot new releases.
In order to change a common or garden best seller to a hot new release first the buyers need to understand the product. Sadly this means that the more complicated the title the less likely you are to get sales. So the English dictionary is more likely to get sales than Daft words and Their Meanings and Etymology. Creativity is not what people look for in titles.
Further to this it helps if it is something well known, but not so well known as to be widely available, for instance lesser known fairy tales, such as the The Wolf and the Seven Kids. Things like Sleeping Beauty have been too widely distributed.
It is a good idea to look at the Fairy Tales and Myth category to see what is currently selling. Of course you can’t copy a story wholesale but change the story (which is out of copyright). In fact you can add your own spin to the story, going into areas that the original story didn’t. The better the writing in the story, the better the likelihood of receiving sales.
Another important part is not too get too greedy. People are more likely to buy cheaper e books, especially from an unknown name. People will expect more for their money.
An important thing is to publish as much as possible; not everything can be a success. You can still get money from publications which don’t sell as well.
Remembering the market is important, people are going to buy Christmas themed stories near Christmas, and Halloween themed stories near Halloween-Sleepy Hollow, and similar. That is not to say these kind of story couldn’t sell at other times of the year. This could also apply to craft based e books, though in my experience they are harder to sell.
The cover is vital, this speaks volumes about how professional you intend to be. Unfortunately hiring a professional artist could cost thousands and generally not pay for itself. Just come up with a design that will fill the screen and that is out of copyright. Clear text on the cover may also help sales.
Good luck in your writing.