I'm still trying to figure out how to do it, but!
I've noticed, long ago, that my voice takes a rather severe change in pitch when speaking in English. And the intonation is very different as well. I'm a crazy, I talk to myself a lot, really, so I guess that's part of the reason. I don't have to pretend. So.
I'm trying to get that to Danish, but it really changes my accent when I do it. The higher the pitch, the more eastern my accent (within the boundaries of the Danish country, of course, and not quite swedish-sounding either ^.^)
And it does sound weird and phony to me when I try it in Danish.
But English, even when I don't pitch too high, I sound much more female. Because of the way I pronouce words, the bits I emphasize, the...the everything. I might sound like a woman with a cold that's been smoking since birth (the cold, actually. Imagine that, a cold with a smoker voice!) but I woman I do sound like!
~Moi