I hate to give what seems an overly simplistic or pat answer, but here goes:
Porn.
Yes, I said it. I don't mean to the exclusion of everything else. I mean, do all the things Birdy suggested, and add in a little dirty movie. For YOU to watch. That's what's great about the internet. Growing info, and porn.

I am crazy about my man. I think he is the hottest thing I've ever seen. But sometimes, whether it's hormones or just plain fatigue, I am not in the mood. Rather than make him go through a dry spell, I will fire up my computer after he goes to work, and watch porn. Even just sort of skimming it. It sets your mind and body up to be more receptive later in the day. And I watch it alone, because that way I don't have to get all paranoid that he's comparing me to the girls in the movie, or that he's fucking me but thinking of them, dig?

I'm on the fence about the political aspect of porn, from a feminist perspective. But I do know it works, so I try to put my ideals on hold when faced with a remedy for flagging libido LOL!