I realize this is an older thread but there seem to be no qualms about it being resurrected, so I'll go ahead and add my two cents.
My birth name can't be feminized, and it's also not a very common name which is something I never really liked about it. So I had to start from scratch, and I wanted a name that was a bit more commonplace. I went through several names I liked and tried them online, but they all seemed a bit pretentious to me. Eventually I settled on either Erin or Lauren. In the end I went Lauren, after two different friends at different times that I thought maybe I had a crush on, although now I'd characterize the feeling as more platonic admiration (that, plus I really liked their names). It feels right. Even being pre-transition and mostly closeted, I find myself more and more referring to myself internally as Lauren, and when I look in the mirror, the person looking back at me is Lauren and it feels like that's always been her name. It makes me happy.
Not sure about my middle name, though. My current one is very masculine and will definitely have to go, but I don't really have any ideas. Thought about Michelle, being the traditional option, but my dad and brother both have Michael as a middle name so it would be a little weird.
I likely plan on keeping my last name, but there's a possibility that may change as I really don't know how my family will take my coming out/transitioning. We'll see how it goes, I guess.