I love these patterns using hand drawn elements.  Thank you Helen for teaching me this very useful method.  Everyday I work on a few of these hand-drawn patterns so I can have a bank of them to texture my little illustrations.  In the fish/submarine picture, I used blend modes to combine my patterns with gray-scale watercolor shapes.  I didn't use it to full advantage, but I textured the little fish with the following "cat face" pattern.