Screw the dividers, get a basket tray.

Not many cooler accessories are worth your money, but a basket tray is the exception. Dividers waste space and make packing a pain. You’re better off using towels or bags to separate things.

A basket tray sits on top, giving you a dry layer for snacks, keys, or anything you don’t want swimming in ice melt. It keeps you from digging through the whole cooler for a beer. Cheap ones from igloo or yeti knockoffs cost like $15 and work fine.

The only other thing I’d consider is a drain plug adapter if your cooler has a threaded hole—makes hosing it out easier. Everything else (cutting board lids, bottle openers, cup holders) is just stuff to lose.