Or, what I'm finding I do, is if I see a cover I like, usually by way of mention on someone's blog, I'll add the book to my Amazon wish list.
For example, yesterday's RTB column by Lori Devoti directed me toward the very cool cover for Gena Showalter's Heart of the Dragon.
I just love this cover! I'm finding I'm kind of big on covers that don't actually show faces of characters. Anyway, I went on to read the blurb about HotD and it looks like it might be pretty good. Except, I haven't read anything by Showalter, plus I just placed an order at Amazon so am feeling like I've spent my book allowance for a few weeks. I put HotD on my wish list so I'd be reminded of it later.
I actually went so far as to hunt down as many of Karen Marie Moning's Highlander series as I could find because I so loved the cover for Spell of the Highlander, so thoughtfully brought to my attention by Sharon over at Write Minded.
I did pick up Hope's Captive by Kate Lyon despite its absolutely hideous cover.
Proving once and for all that you definitely can't judge a book by its cover.