I didn't make them. To make a character, I just choose the best one from bunch of my doodling. For 'My Last Life', I tried to make one, but only the face from 3 angles views, that's all. I don't know if that still consider ref sheets. I figure I need it at least the faces since, I have hard time to have the same 'look' for each character when changing angles. If you don't have this problem, or you just draw for yourself you really don't need it.
