It took me a decade, but I too can wail like a banshee. I am now learning how to sing clean, which may take another decade for all I know. The most important things I've learned are this:
never sing something that hurts, just work up to it, and
always do things personally. By the first, I would give the example of
that scream in "Deadhead". When I first heard it, I used to srtain my voice to try and hit it every time and fail miserably. NOw that I've trained myself, I can hit it without trying, and if I had to try I would be damaging my chords to do so. For the second, I'd give the example of Attila Csihar. I spent my "black metal vocal training" trying to emulate his voice, and when I finally got my throat round his repitiore, I realised my own voice does things that I have not heard him do. I may not be able to belt out on stage for hours on end (although this remains to be tested), but I use my own voice to screech, and shall use my own voice to sing when I've got that down properly. This, I feel, are the most important points.
Still, I'm lucky enough that Dev's vocals can only go about a tone higher than mine, it seems.
