Can anyone recommend any approaches for improving the volume or resonance of my voice?
I've had no formal vocal training whatsoever. My voice is baritone and naturally very quiet, even when talking I feel like I have to strain to be heard and I'm forever having to repeat myself.
Also, I've noticed recently that my voice can change texture a lot. Sometimes it feels rich and deep, and then at other times it naturally feels more comfortable at higher pitches and sounds thinner, even when speaking. I hate this because I feel like I sound like a girl!