I work in a warehouse and I don't 'kit up' to ride, so the dress code is lax compared to most here. I do keep in one locker:

-Clothes: jeans, shorts, socks, underwear, a t-shirt, and I think a pair of khaki's.
-Personal care: towel, deodorant, toothbrush and travel sized toothpaste.
-Food stuff: plate, bowl, and a spoon. Also a package of instant oatmeal and a cup of soup (Ramen) reserved for emergency use.

I keep a pair of sneakers stashed in the entertainment center in the break room. My hat and man purse goes into another locker. Everyone at work but me drives, so I don't have the option of keeping my junk in my trunk...