Stick to simple, fast, and easy recipes. And improvise! Don't buy a giant bunch of expensive fresh herbs if you know you won't make the most of them. Don't have oregano? Try thyme. Let thinly sliced onions stand in for shallots. Use white wine vinegar instead of Champagne vinegar.
What are your tips for cooking, eating, and shopping on a budget? Do share them with all of us below.