Gonna make this short and sweet, little background, I play the saxophone and I'm pretty good, started talking like how I breathed into the sad and my voice got a lot better. Basically breath into your belly(we all probably know this part) not just your belly but your back too. Flex your core to push the air out and your voice will sound fuller (at least mine did) might take a while to control the air though. This is a pretty good guide, only needs watch like 2 mins to get the idea, also speak from your mask not throat. Your mask is basically from your chin to your nose. Hope this helps

https://youtube.com/watch?v=boTaq9bITFc