Reusable grocery bags and tell the cashier you don't need bags when you're only buying a few things (just carry them out). Cashiers always default to putting even one item in a bag but just need some prompting to not do so. My wife goes so far as to take things out of the plastic bags and leave them for the odd occasion that the items end up there during checkout. Small trash cans usually don't need to be emptied every week, unless they contain organic matter. And when small cans do need to be emptied, you can often dump them into your larger weekly trash bags.
