I absolutely write more smoothly when my desk is nice and clean. It keeps me focused on the words and the story flowing out. So before I began NaNoWriMo I completely emptied off my desk and cleaned it. It made a big difference to me! I even cleaned off the bookcase beyond the desk so I didn't have clutter in my line of sight.
Doing a desk organization is a great thing to do no matter what writing project you're embarking on!
It's well worth the relatively short time it takes
Do you write better with a clear desk?