This is not ideal, of course ... but pitch range has less to do with it than you might think. Bea Arthur had a deep voice, and I doubt many people hearing her assumed she was a man. Even if you're a low baritone, you can probably edge up toward Middle C without straining. If you can get into that range, you're well within the lower end of the female norm.
She actually has me a bit higher than that.
More important than absolute pitch is pitch inflection -- letting the voice rise and fall. Men tend to talk more in a monotone. They will push certain words louder for emphasis. Women start with more pitch variation, and their voices rise in pitch for emphasis.
That is exactly what she is trying to get me to do.
This summer I wrote a blog entry of voice tips. You can find it here:
http://jennawillow.wordpress.com/201.../other-voices/. One tip I picked up recently on YouTube was, hydrate! Drink plenty of water so your vocal cords don't dry out. And instead of coughing (which male lions do, I believe) when your throat is scratchy, learn to swallow.
Again, she made that exactly that point. Before we started she brought me a glass of room temperature water to use during the lesson.
There are several good TG voice tips videos on YouTube. (Search for transgender, not crossdresser. The crossdresser videos are ... well, I won't criticize, I'll just say I see no reason to watch any more of them.)
I saw some of them. They were helpful, but I really wanted real time live feedback, so I sought out a voice coach. (Her voice is wonderful, by the way.)
P.S.: That, by the way, is an example of feminine voice in print. As a guy, I'd probably whip out a few choice adjectives or a rude metaphor to describe the CD videos. As a woman, I'm more polite and considerate of others' feelings.