I have been working on it for over a year now. Persistence and practice are necessary.
If you have the time and money see a speech pathologist.
I had the time, but not the money so have been doing it the hard way. The very first couple of things that are really important are:
1) Don't hurt yourself. You don't want an injury (probably of the vocal cords) to deal with. Be careful, go slow, and when you get a sore throat; give it as many days of rest it needs to feel better.
2) Hydrate, Hydrate, Hydrate.
There are several tutorials on the internet you can search to find them. Some are backed up by heavier versions that you can buy.
The best I have found so far (notice the so far, there may be some that are ever better) can be found at
https://www.youtube.com/watch?v=mO41CpU ... F3C587C9A2" onclick="window.open(this.href);return false;. I like it because it is through, explains a bit about how a voice works (it isn't an instrument, it is an orchestra), and deals with resonance distinctly from pitch (terms they explain) is an intelligent manner.
A couple of things not mentioned elsewhere that have helped me:
* Have a recorder available. E.G., a dictation app on your smart phone. Record samples and listen to them as critically as you can.
* Try to make the "voice in your head", i.e. while thinking to yourself or reading, sound feminine.
* Don't even try when you have a head cold.