The idea is to avoid making your desk space a repository for dreams and ambitions. Desk is your cockpit and you are the pilot.
To begin with, let us consider the objects that are essential and deserve the presence on your desk. You definitely need a good computer, an expensive monitor and a quality keyboard. You also definitely need a mouse as a trackpad is a fast way to get carpal tunnel syndrome.
In general, it will be sufficient for you to have one expensive pen and a specialized notebook (e.g., Leuchtturm1917). There is no need to clutter your desk with dozens of ballpoint pens.
Another problem object for your desk is so-called personal shrine effect that refers to an abundance of photographs that should be kept either on a credenza or shelf, but not on the place close to your keyboard.
If you do not need that stapler or tape dispenser in at least a month period, put them aside. Another thing that is essential for your desk is cable management.
Cables under your monitor is a sign that you are a person who lacks the ability to control his life. Try using zip ties or a tray in order to hide your cables.
Coaster for your drinks is required in order to avoid leaving unpleasant-looking ring marks on your desk. One plant (e.g., a snake plant) will make your desk more attractive and require almost no effort from your side.
Finally, your desk should not contain letters, business cards or any other kind of paper. If your desk is full of things, then even a glimpse of wood or laminate under it is hidden.
Your desk should be your runway, not a runway for chaos.