This issue of cover art is never far from my mind. It shouldn't be from yours either unless you're just going to contract it out and have someone you trust already lined up. If you're going it on your own, this is something you should be thinking about a lot because it's important.
We've talked about bargain stock photos--haven't we?--but I have to admit even though a good number of my covers do have photos on them, I'm not convinced it's the best way to go.
Some months ago I saw the cover Carl Graves did for Konrath's Trapped. It's just the title but the text effect is exciting and eye-catching. I'm sure it would work for a paper book but I know it works for digital.
I'm trying to think where I was yesterday and saw a website with a background image that impressed me. It had great juxtaposition between dark and color, and the text was strong. Maybe it wasn't that strong since I don't remember the words, but, visually, it was a grabber. Every time I see something like that, I learn, I take some information away.
Look at the covers other people have done or have had done and learn. What works for you? What doesn't? How can you, at whatever skill level you're at, approach that same effect? What are you trying to convey about your book with the cover?
Back to the Flash title/technique, what I felt was lacking as I worked along was the capability of multicolor. There are often a number of ways to get to the same place with Photoshop. When I googled the question, I got back a number of solutions that were off the mark. Then I saw one I thought was also off since it was about turning a black & white photo into something with a couple of different colors. When I read the steps I was unconvinced but when I tried it out, I was pleased. I don't think this is the only way to get there, tho, and now I have a couple other ideas to try on my own.