It's one thing to have a cup and know how that fits, and be able to reference from there. But before you buy one, how do you know what dimensions you need?
It's not a question *I* need urgently answered... I think I've figured out what my needs are. But it was my biggest confounding factor at the start of my research, esp. considering every question of "Which cup should I buy?" is (rightly) answered with "Here are the size charts, buy according to what fits best"! So I'm curious how others have solved the question for themselves, whether veterans or newbs.