I unleash creativity in a number of ways. The most successful for me is to buy new beads and findings on speculation. By that, I mean that I have no clear idea of what to do with them at the time I make my purchase. I take them home and throw them on my desk and let them move around and suggest to me what I should do with them.
Occasionally, I will have a specific design in mind when I buy something only to find that when I get it home, it tells me to do something else entirely.
Color plays such a big role in jewelry making (even if you are working just in metals), that sometimes I will just sit and look at clothing catalogs and then inspiration strikes.
I have a day job in a jewelry supply shop and the thing I hear most from new customers is that they would like to make jewelry but that they are not creative. We all have creativity inside of us. We just have to find the right key to unlock it.