I almost always pay with cash. Indeed, I have never, ever used my debit card for a purchase and frankly, I wouldn't know how. I use credit cards only for on-line or major in-store purchases.
Our planner seems never to have cash on him.
I'm guessing this is an age thing: I'm within shouting distance of 50 and he's not yet 30.
What about you? Good Old Greenbacks or plastic?