This is really random, but something I thought was pretty helpful. See this cover:

Her dress looks out of place, right? Like the whole thing is a dark cover, but her dress is rather bright. So, I wanted to try something that I had used a little while ago, and decided to try painting on it. So, I opened PicsArt, and opened drawing. I used black, and colored over some of it, whatever much I wanted it. Now, don't panic if you do this and it looks bad at this step! Open layers, and try some different filters on it, like overlay, darken, ect.

This is how mine turned out^^ I think I could have done a better job doing it, but the point is that sometime painting can really help, if you just try using the filters on your layer of paint :)

Another thing drawing is useful for is adding color to the cover. For example:

the gold was completely colored in, and then I believe I used the filter 'soft light' but if that doesn't work for you, try some other filters.

<>Evara<>