A couple of years ago, when I was thinking a bit about frugality (as in; “Hey, that’s a characteristic I should have more of), I came up with the idea of a “Zero-Six Week”. This is a week where I am only allowed to spend money on one of the days (typically a Sunday). The aim is to buy enough necessities on the Sunday to see me through the week, and not spend any money at all the rest of the week. That means walking everywhere, making all the meals for the week, etc.
To date, I think I have maybe done it twice, although I am thinking of doing it next week.