Make as many things from scratch using basic ingredients as much as possible. I make meals and mixes from scratch as well as household cleaning supplies and anything else that I hear about (but remember that homemade does not necessarily mean less expensive – you have to do the math and see when it pays to buy things premade). I use “staple” items to make things (fancy ingredients are expensive!) and try and stick to recipes that only use a few ingredients (saved time = saved money).
I also buy what I can used (clothes especially), and I put out the word when I need something and people sometimes give me things free. I also don’t turn down free things (food/clothes/etc.), in case the offer doesn’t come again.