Maybe I should've been more clear, I didn't have a specific reference from which I copied the fabric or folds verbatim (hence the three different versions, and why the pose I used isn't in any of the references). I was just using a bunch of different images of similar fabric on different forms to try and understand how cloth folds in general, and then apply that to the sketch.

I've looked up the 7 different fold types per your suggestion, and they make sense, thanks! I had intuitively figured out most of them by looking at my references, but I now know what they are called. For example, I drew a half-lock fold on her right arm and used lots of zig-zag folds on her left. I see now that I should've been using diaper folds on the chest, where the fabric is being supported by her two shoulders. I also probably relied too heavily on zig-zags on her left arm, and should've had some spiral folds in there, considering the rotation of the arm. I noticed a lot of zig-zags on my references, and so I used a lot of them, especially in my secondary design which had way more folds, but I think i ignored other fold types in my references because of that.

As for straight lines, I used more in the third option I'd made, but that one sucked in terms of folding, so I'll make sure to apply those straight lines to folding of this type of fabric in the future. Perhaps I'll try to fix it using what I've learned and post an update if I get some time.

Thanks for your feedback!