Aside from being a shoe junkie, something else I'm guilty of is buying ingredients without actually having a corresponding recipe. I love jarred items in particular, like marinated artichoke hearts and varieties of olives, pearl onions, and baby dill pickles. Eventually I end up with shelves of lovely ingredients with just a few random basics, and I'll spontaneously commit to two weeks of creating meals with primarily what I have on hand. Instead of spending money on additional groceries or eating out, I'll rely only on what I create in the kitchen.
During the two weeks the only food-related items I'll allow myself to purchase are fresh fruits and vegetables to make the pantry crafted meals more healthy and colorful, and I'll only buy them when I have a specific meal in mind so that they don't end up going bad before I get around to using them. I also give myself a budget for these items so that I don't go crazy at the farmers' market. Week one of the challenge is usually pretty easy and it's fun creating my own dishes, but toward the end of the challenge my drawer full of takeout menus starts to taunt me.
This challenge is always satisfying in the end — it's a great way to use random items you have lying around save money by restraining yourself from buying unneeded groceries and eating out. And, hey, depending on how stocked your kitchen you could always extend the challenge another week.