i use those sport sandals with a strap on the backs, beefier than tevas but you get the idea. i like having backs so i can't accidentally kick out of them on the wet deck. another pair i use sometimes are plastic birkis, the kind with two straps across the top. they have those deep foot beds, so i'm less likely to have them come off. normal little flip-flops aren't secure enough for me, and are very slippery.
i second the chapstick, water, microfiber towel (try bed bath & beyond, a travel store, or even target), hat, hair claw (i just rinse & stick it up, i don't brush or condition or anything), and large ziplocks. i take big bulldog clips (about an inch, not the 3 inch ones) in case it's blowing and i want to secure the wetsuit while it drips. i take a book, but i take a book everywhere, so i'm weird that way.
i hope you have a blast!