Let's face it: human nature will prompt us to purchase more things than we actually need when we realize we have more money to spend. However, by only purchasing what you need, when you need it, you eliminate wasting your money. Many times, in stocking up on groceries and other products, plenty ends up being wasted.
Avoid waste at home by purchasing just what you need each time, then use just enough of what you've bought so it lasts twice as long - you don't always need to use the amount suggested on the packaging.
This may seem the opposite of what I usually say about building up a stockpile and buying in bulk, but if you are just starting out living the Cheapskates way, take your time and think about each and every purchase. Then you will know what you use, how much you use and how often you use it.
Those tins of smoked oysters might be on sale for a rock bottom price, but if you only use one tin a year, buying a box, no matter how cheap they are, is a waste - of your money, your space and eventually the smoked oysters because after a couple of years you know you'll throw them out.
When you do stock up, only buy what you can use in a reasonable timeframe - think of those smoked oysters - and you'll save money, time and energy and eliminate waste.