One needs to be particularly careful when closing a Tenkara rod after a day astream. The vast majority of Tenkara rods are broken while collapsing the rod. Cold, wet, tired hands don't help. It helps immensely to be able to get a good, firm grip on the rod, in order to be able to apply precise and controlled force while closing the rod. A good way to get a firm grip is to use a rubber grip pad.
A very effective grip pad is a piece of rubberized drawer liner -
Another option are rubber jar lid grippers -