Falsetto is a totally unnatural way of speaking. It's because it sounds too fake and it's too airy. It's totally totally damaging to try to use falsetto to project your voice. What is really important is that you lift your voice box using your neck muscles, but you can't go over the top, just find a happy medium and that allows you to intonate properly. But I guess I can't help that much because I have always done this subconsciously and now I'm stuck with a voice which is 270-310 Hz, which is just child range, if I hadn't done this, I would have a voice around 190-220 Hz. Anyway, falsetto not only sounds unnatural, but it also is very monotone and lacks power and melody. Also, the fact that resonance is still maleish can get people read. Go for something that will allow your voice to have acceptable intensity and pitch. Falsetto voices looks innapropriate on adult women and speech theraphy is immediately recommended for women (or men) who speak like that, so this isn't just a gender thing.
The most important thing beforehand is to remove chest resonance. Women speak from their heads and necks, their voices resonante in upper cavities, while men's resonante on the diapraghma. Once you do this, your voice will sound better not matter the pitch. But pitch is still key to get your voice right. If you're young like 15-25, you could aim for 200-250 range, average speaking voice around 220. If you're older 40+, then under 200 mark would be good. You have to aim for at least 165+ Hz, this is the point where people start getting gendered female on the phone. Combined with right resonance, perfect! And voila! Oh, I almost forgot, you could also download praat to analyze your voice's pitch and resonance and documment your progress. It will be useful. Also sometimes praat is tricky when it comes to analyzing pitch, so hear the recordings as well once to see if it sounds right.
Good luck with your training!
