1) Not going out to dinner. If we really want to get spoiled, we do lunch. Meals are cheaper (with better portion control) and we don't get the bottle of wine. Or we get our own appetizers and split a main course. It's usually more than enough food for the two of us
2) Making a budget. It's hard sticking to a per week allowance, especially when unexpected costs come up, but it lets us save for the things we really want.
3) Minimize our miliage. We do our best to cut down on our kms by only heading into town when we have more than one reason to do so. We combine picking up necessities with work, or seeing a friend. It cuts down on gas and future car expenses.
4) Shopping responsibly. If we need something, we let the other person know, and combine our errands. If I go out to get jeans, I have no excuse to come home with shoes and a top.