Batch cook meals - make up huge quantities of things like soup, stews, shepherd's pies, cottage pies, chillies, curries etc - then divide them into portions and freeze them so you have instantly nukeable ready meals for if and when you are too tired to cook in the evening - and get everyone in on the cooking so it's not just you doing it!

Like Lou says, do your shopping online if you can - stops you buying junk you don't need

Go through your closets/cupboards etc and get rid of anything you don't need/want - and try to sell it either through e-bay or another auction site, or a garage sale. I'm currently in the process of selling a whole lot of my books and stuff to raise money.