My husband and I do our weekly meal planning before we go to the grocery store. This gives us 2 advantages.
1. We don't have to ask the dreaded question: "What are we going to have for dinner tonight?"
2. By sticking to the list, we only buy what we need, which saves money too.
We have a dry erase board on our refrigerator where we list all of our shared meals for the week, including weekends. (You can pick one up from an office supply store.)