Go through Mehwish’s Voice Training Guide. While it is primarily aimed at trans feminine training, it does contain the necessary information to be used for trans masculine training as well.

You can find examples of how control of different aspects of your voice sounds in the Selene Archive.

Once you understand the basics, the primary thing you’ll need is consistent practice. Use your voice wherever you can — reading a book out loud, talking in random voice chats, thinking out loud. Get creative.

Feel free to ask for advice in the voice training channel.