Shell 1

Looks like the right category to me. Wow, cool - I can't cross-hatch to save my life! This looks really nice and I admire that you practiced on a shell - they're all curvey and complex and wierd, but this looks really wonderful! It has an excellent 3D-ness. The one thing I'd suggest is to add more darkness. Now, I don't know a first thing about cross-hatching, so I don't know if part of cross-hatching is to keep constant pencil pressure, but if that's not part of it I'd say make some of the shadows a bit darker while you make the lines denser. Again, quite admireable, looks great!