Throughout the writing process, I make mock-up covers for my novels.
They're just for fun and As you'll notice, I tend to lean toward dark covers.
The earliest version (I have) is on the left, and the latest version is on the right.
In this instance, you can see that the novel's title changed along with the cover.
Both for the better, I believe.
These two sets of novels both have two cover options...
a first and a second, I'm not smitten with any of them.