Freeze any leftover vegetables. They're fine in a stew or a soup.
Freeze leftover wine and add it to soups, stews, casseroles, gravy etc.
If a full sized breadloaf is too big and goes stale, split the loaf into two as soon as you buy it, and freeze half.
Buy wholesale packs of meat and split them up to freeze.
Don't leave any electrical appliances on standby - they are still using electricity.
Don't buy anything that is a "bargain" unless you geniunely need it or will definitely use it.