Yeah, a messy desk may work for your creativity but if you want to stay focused, you may still want to apply some sort of organization with your tools.
Keep the things that you use daily close and visible. If you like spreading out papers while working, make a room for that, so you won't feel cramped. Store the documents and things you seldom need off your desk to keep your workstation less cluttered.
Try: Simmer Stone Rose Gold Desktop File Sorter Organizer, $18.99