agree with most pp's here..... my method is knowing our habits,what we will use in any given,and stocking accordingly- I stock enough for 2-3 months of just about anything that I can get for cheap,no more. There is a fine line(maybe not so fine

) between stocking,and hoarding....(think spare rooms with 237 cake mixes on the shelf)
for instance- I have recently stocked our toiletries closet, each item has it's own row,so I can easily see if we start to run low,like t.p.,shampoo,soaps.
fully stocked for us is approx 3-5 bottles of shampoo,enough t.p. for at least 2 months.I usually won't restock till it gets low-otherwise I'd end up with a closet full of unused 'bargains'.
food, you keep a list of what you have, and every 2-3 months, I use it all before buying more. Make a realistic budget,and keep some ready for good sales, but make sure they're GOOD if you intend to stock up.
I'll usually buy our meat once a month,since I know approx. what we will use in a month. Freezing is a great way to divide,and use all your food you buy.
Just keep track ,so you don't waste what you have.
I only stockpile certain items, the more expensive things. This way my extra work has a point,I don't put a lot of effort into saving a nickel on pasta,since I know it only costs about .50 any given week anyway.....
also know that most sales repeat every 6-8 weeks.