The easiest way to stockpile is to have an amount set aside each week to buy a little extra. It might be as little as five dollars. When something that you normally use is on sale, you would use that five dollars to buy as much as you can.
Right now is a good time to look for deals on "health foods" like yogurt and Kashi type cereals, frozen veggies, and pasta sauce. If you're a couponer or you want to be one, check out The Storehouse Ministry group on facebook, that's where I post all of the good deals for my area in St. Joseph County in Michigan.
NEVER stock up on something that you don't normally use. ALWAYS check the expiration dates. Make sure you have room in the cupboard/freezer for your purchase. I've seen people who keep extra food tucked under the bed in totes, that's too much in my opinion but if it works for you, go for it!
Once you start stocking up regularly, you will see the real benefit to it. Recently, there was a small winter storm forecasted to hit our town. From what I heard, the stores were chaos. I don't have any personal experience with the chaos because I didn't NEED anything!
Your shopping habits will change from buying your weekly menu to buying as things are on sale that you normally use. It's not uncommon for me to buy a large quantity of pasta once or twice a year. I don't buy it when it's not on sale. I'll never forget the day a few years ago when I told a friend that I'd just bought 30 jars of pasta sauce because it was less than 70c a jar. The look on her face was priceless. I explained that it would be enough to get us through the year but she still was confused. WHY would I need to have so much food on hand? I don't NEED to but it sure makes life easier when I get too busy to shop. My family still has food to eat and toiletries to use, even if I go a month without a shopping trip. It's a great feeling to be able to rely on my husband to grab a gallon of milk on his way home and KNOW that that is all we need to take care of our crew.
If you have any specific questions about stocking up, please leave a comment and I will do my best to answer your questions!