I have started actually trying out voice training excercises, and have realized that my vibes based approach of just humming music as high as I can without my voice breaking, maybe wasn't that bad after all.

Also imitating the sounds my dog used to make, has given me a bigger vocal range.

I am still going to continue with the actual excercises, but I'll also continue just playing with my voice while having a walk or something. I used to sind a lot as a child, before my voice dropped.