A towel with a clip ring or something similar so that you always have a towel closely to wipe your hands.
Marker buoys if you like to use them
I've seen pictures of something made out of PVC that makes running trotlines easier---its horseshoe shaped, goes over the side, and supports the main line while you run it.
Milk crates----they're always good for storing something, especially jugs if you use pool noodles
If you can either quickly or quietly switch out shells, you can bring home almost anything.