In the Stone house we have a two definitions for clutter.
Melody's definition of clutter: Anything that doesn't have an explicit home within the house.
Luke's definition: Anything of Melody's. Especially items on surfaces, i.e. on counters, dressers, or tables.
To combat the clutter I purchased a clutter basket. The idea being anything without an explicit home is placed in the clutter box and once a week we go through it and find homes for items or eliminate them.
Here's another blog about how to deal with clutter. Good luck in the battle against stuff!