Youtube is a great area to start. A lot of thots who go into fashion design knowing nothing about art and anatomy leave with a really good sense of it. I recommend Zoe Hong.>>3637880
I dont rely on one aspect to teach me, I combine them. i.e, you draw a pose with some basic lines to 1. learn where your fabric is gonna lie on your body and 2. approximate height and width of your body. After you do that then you draw your fabric over it, using your lines and your body's pose as a guide. Im not saying to completely skip studying musculature in the nude and such, but for someone learning to draw with minimal experience, I honestly think fashion is one of the best ways to learn.