This trick is so simple, you’ll be slapping your forehead that you haven’t thought of it already!
Store milky products, like milk, cream, yogurt, cottage cheese, etc., in the back of the fridge, where it’s coldest. This applies too, when you pick them up at the store; choose containers farthest back in the case. You’ll find these items will remain fresh longer.
A tip for cottage cheese from rworange: store it upside down (in the back of the fridge, of course!). This is said to create a vacuum seal that helps keep the cottage cheese fresh.