>>1784681I can only think of two ways I'd go about it.
A: stack hook-like shapes on top of one another to keep the fading effect of the lines in the middle that gives the impression it's really twisting.
B: Do it in 2 steps. Do the full exterior as one shape going all around and then have each bumps reach one another with lines.
Personally, I'd go for method A on this image.
