Whenever you go to the store, always buy something extra to put back for preps. For the longest time, I would buy 1 thing of coffee and 1 (2) lb bottle of honey (barter items). Now I have 15 cans and 20 lbs of honey saved up. Then move on to something else. Buy a couple pounds extra of dry beans and rice. If you look under "food storage" you can learn how to store properly so it last for years and years. There really isn't any excuse not to. If you are on a tight budget, spreading out your purchases like this over time will help.