Keep everything visible.
Does this mean keep everything out, and never use closets, drawers and pantries?
NO……it means, even when using these spaces, organize them in a way that allows you to see everything you have. Which brings us to the priciple:
Have enough room for everything you store.
Don’t use drawers to jumble piles, or stack items on top of other items – this leads to “out of sight, out of mind” syndrome, which has us hunting frenetically for items and re-purchasing what we already have.