We use a mixture of these things. Expedit boxes for each person is by the door. Bags for swimming, dance class, scouts, hanging in the utility room and re packed straight from the dryer.
Plastic drawers/boxes on top of fridge for annual passes, things to do, filing, children's art work and memories ( then transferred to the loft)
Notice board with clips to hang important letters
Shared family google calendar that au pairs also add to
Two weekly tesco deliveries on sat and weds that au pairs can add to
Two wipe clean weekly calendars on the fridge - one for the werk's schedule and things to remember (trips etc) and one for the meal plan
Shopping list and to do list next to it
Every Saturday when we put the shopping away, I cross reference the family calendar, my work diary, birthdays, meal plan, shopping list etc
We have 4 children and with my commute I do 13h days
Oh yes, filing
I have two boxes per year
Jan- jun
Aug- dec
Chuck everything in
Put box away
Every few years I get out the oldest boxes and throw most of it away
I rarely need anything from the filing system, it's quicker just to leaf through occasionally than to file it all in immense detail