One bit of advice has stuck with me ever since I started this indie author thing:
"Don't be afraid to change your cover."
I have long resisted this idea, though, even as I've seen that the books shown on my books' Amazon page's "Customers Who Bought This Item Also Bought" have covers very unlike mine. Those covers invariably feature a good looking man or couple, some with a musical instrument or a concert audience to suggest the rock star theme.
Though I absolutely adore the simple covers I already have (especially when they are grouped together), I have to admit that they may not be as compelling as they could be to the average reader.
The other bit of advice that I keep thinking of is that your cover should immediately show the reader what your book is about. Mine are contemporary (rock) romance, but the visual of, say a tangled up mic and cord for Tangled Up In You may not evoke that as quickly as it should when taking into consideration the need to express this within a glance.
So, I've commissioned new covers for the Rogue Series Novels in hopes of producing a look that might tempt more of those "one click" buys. It will be an interesting experiment to see how/if this makes a difference.
I'll be sure to share the new covers here. In the meantime, here's a bit of eye candy that'll give you a sense of the new direction.