Stupid error I'm gradually slowly getting rid of making --
1. Go to the market or grocery store.
2. See that vegetables or meat or whatever costs 50% or even 100% more than it theoretically should cost. (EX: $4 for a big can of vegetables.)
3. Don't buy the food.
4. The next day, run out of food at home.
5. Go eat out at an expensive and inconvenient restaurant instead.
Double check your alternatives. It's better to take a mediocre satisficing deal in an area that's not mission critical if your highly likely alternative is a much worse deal.
Maybe this is obvious on paper, but surprisingly unintuitive to people with the "maximizer" type personality. Double check those alternatives.