Quick, look in your pantry or cabinets right now. What do you see? Do you see seasoning or sauce mixes? Cans of soup? Packages of cookies?
I won't tell you to throw them out, but do use them up. Then don't buy any more, if you want to save money. Instead, buy ingredients.
If you have a favorite mix on hand, like that for tacos or stroganoff, look at the ingredients. They will be listed in order of quantity. You can estimate how much of what (skip the stuff you can't pronounce) and you can experiment a little until you have the exact "recipe" for that mix. Make your own and keep it on hand, or just write down the recipe and use it each time.
Do that with every mix you have and those that you want to buy. I have even stood in the grocery store and written down the list of ingredients in a mix that I wanted to try.
It's easier than it sounds, because there is really no magic to these mixes. The only things you will miss are the preservatives, artificial colors and other chemicals they use to make their mixes last longer or look "better. You'll miss having to pay for them, too.