I am not a very organised person with regard to time, but my wife and I plan a few days ahead and it works (without children). We don’t have a dedicated time for the planning itself, nor do we have regular meetings of any sort. We mostly wing it, but in a mostly responsible fashion, by which I mean we always end up doing what we set out to do, even if slightly late. Generally, I go by this : whatever it is, do it as soon as you can. Good luck