One of the great things about sitting in the "picnic" area of Costco is you can sketch people, galore. I discovered the ones in line don't move as fast as those walking toward the check out line, but you'll see one of those here too (bald-headed guy going the other way).
Another great thing about having a sketchbook while my significant other shops her way through the aisles for stuff she likes best. Later she came and got me and we checked out the meats, the cheeses, the wines and liquors, and the books.
The polish is always good here too. I soak it in mustard and chopped onions: that's all. Tasty.
6x9 Super Aquabee Sketchbook, Noodler's Lexington Gray ink, watercolors.