File, don't Pile - Breathing Space Blog
What you keep on top of your desk is uniquely individual. Your goal is to maintain the optimal number of items on and in your desk; enough so you function efficiently while there, but not so many that clutter inhibits work. Hold onto items you use at least once a week, but don't store those supplies too close by. Recognize that your desk drawers are not for storing supplies per se. You may store a pad of paper, but not pads of paper. You only need one pad at a time, and the general principle is to have the smallest number of a necessary item as you can get by with.
The fewer things you have in vital work spaces, the greater the sense of control you have over your immediate environment. For instance, if you choose to use one of your desk drawers for file folders, then these files should be as thin and potent as you can make them. Once your desk and flat surfaces are under control, you also gain a heightened sense of control over your time.
You might wish to place sentimental and familiar items, such as pictures, plants, and motivators near your desk, but not on it. Install items such as full spectrum lighting or ocean-wave music that support your productivity, efficiency, and creativity, near your work space, not on top of it.
From now on, manage your desktop as if it's one of the most important elements to staying organized, because it is.