At the end of each day you should clear your desk. This means, for example, securely disposing of Post It notes, keeping written notes in a safe place, and ensuring that any removable media isn’t lying around.
Keeping desks clear of clutter is less about making the office look smart, and more about preventing the theft or viewing of sensitive information. Paper with such information is available to prying eyes if it is lying on a desk rather than locked securely away.
You will be more conscious of the whereabouts of files if you store them away each day.
Keeping your desk clear encourages privacy in the workplace.
A clear desk will impress your visitors and welcome them into your ordered, stress-free office. The surprise visitor will no longer be a concern if desks are organised and presentable (cleaning staff also have access to work areas).
If files are stored in the same place away from your desk they will be easier to find.
A clear desk promotes concentration and may reduce stress.
For these reasons it is good practice to clear the desk at the end of each day and this practice is recommended.