Whilst I always drew mine with a somewhat fuller figure, as someone who has done a heckton of hobbyist fashion design (which is to say that I sew clothes and costumes, and I'm shit at following patterns so I do stuff myself), I actually really like the stylised proportions used in fashion design.

At first, I started out drawing figures that were more anatomically correct, but I ended up switching to a more stylised design; it made it easier to think in the broad strokes that were helpful for the early concept design stage (for instance, figures a typically drawn 9-10 heads tall rather than a more realistic 7-10 heads). Although, like I said, I tended to draw mine with a bit more junk in the trunk (and the bust), the figures were still far more slight than I actually am. For instance, although I'm quite broad shouldered, I found that using a croquis (this is what they call the figure templates used — it's French for "sketch") with fairly narrow shoulders made it much easier to tell from the concept sketch whether the garment was going to include structured elements near the shoulders.

I did do sketches that were more anatomically realistic once I got further down the design pathway, and was beginning to think more about how to actually execute the ideas, but the stylised drawings were always the thing that made it easiest to see the overall idea I was going for.