A desk does not need a complicated system. Three clear zones can give the most-used objects a consistent place without filling every open area.
Zone one: the work field
Reserve the center for the keyboard, mouse, notebook, or primary task. Choose a mat only after measuring the objects that must fit together.
Zone two: the reference edge
Place one active card, tablet, or folder above or beside the work field where it remains visible without covering the center.
Zone three: the return edge
Choose one tray or bin for tools that move in and out of the main field. Keep the category narrow enough that the container stays readable.
Keep a clear margin
Open space is part of the layout. Do not fill a gap simply because a new accessory fits there.
Test the reset
At the end of a work period, return each object to its zone. If a product creates another pile, reconsider the category or its placement.