It's just been two month or so since I decided to make it a habit to only shop with a grocery list. It's working out well; I spend less money and I'm not throwing away lots of uneaten produce anymore.

Here's what I do
- During the day, if I use something up or notice it is running down, I jot it down on a piece of paper.
- Then, before I go shopping, usually the evening before, I sit down and add anything else I think I need. I then order the list according to store layout. I do this for every store I plan to visit. (It usually fits on the same piece of paper).

This doesn't take me long, since it's just me and the rabbits.

Because I have no car, and have to carry my groceries home, I do go grocery shopping two times a week. This allows me to be somewhat flexible in terms of meal-planning. Especially when it comes to produce. Maybe you could schedule a second, shorter trip to the store during the week? This way, the pressure to make the "right" decisions regarding every meal for a whole week could be lowered.

Once I'm in the store, this is my one basic rule:
- I don't buy anything that isn't on the list except if I clearly remember thinking about putting it on the list but forgot.

As I said, it works for me.

Good luck!