Nice drawing, it has really cool textures! Though for this assignment, don't worry about adding shading or smaller details, as the focus is entirely on the outline. I think your outline already shows simplification throughout and it feels very fluid, though I would suggest breaking up some of the more complex curves, like the one for the largest shell section, into more distinct and simpler lines. You can even use more straight lines to balance out the curves as well. That way. there's more line variety and the drawing has more clear simplification.