Painting Shells

I painted these with inktense watercolours and a Faber Castell small nib ink pen, but I feel that probably acrylic would have worked better than the watercolours.

If you are looking at these on a large screen, bear in mind they appear considerably larger than they actually are.  I am wondering if I should adjust them to look smaller: on my screen, they are 2-3 times actual size, and look terribly clumsy as a result.