Last summer when shell-bags (and shell bikini tops) were all the rage, I got caught in the wave and jumped on the bandwagon. Made one side of it, got busy with other things (as it usually happens around here) and completely lost interest in it. It became a UFO. 
Now this summer, as I wanted to have a separate bag for my shells and sea-glass bottle, I took it out – but there was no way I would crochet the other side; besides I needed something smaller, so I decided to work with what I’ve got and simply just folded it, sew the sides and crocheted a small handle. 
It proved to be practical and usable this summer. 
P.S If you are into shells, I’ve got a pattern for some interesting ones.