Since I have been on SSDI I have a certain amount I allocate for food each month and that's it. I have to stay within that allotment. I use coupons but before any shopping trip I take inventory of what I already have and what I'm going to need. I also make up menus to follow that allow for leftovers.

Another trick that works really well is the "cash only" rule. I take a certain amount of cash out for groceries, gas, etc. and that's all I have to work with. It really helps to avoid the impulse buys at the grocery since I know I only have a certain amount of cash to spend. I leave my debit card at home locked up in the safe.

I have not used my credit card at all in over a year. I only have one now and that is used only for emergencies. It stays locked in the safe also. I really don't use credit at all but I've found that it's just about impossible to not have at least one. If it is used it's paid off the same month.