I cannot stand clutter so to me it is very important to keep myself organized. If my desk has sticky notes all over the place, files here and there and papers, papers, papers, then I begin to feel buried and out of control. I need to be organized so I can think and function better.
I have found what works for me is having a place on my desk for everything. If it has to do with accounting, I have a bin for that. If it has to do with scheduling meetings, I have another bin for that. And if it has to do with waiting, any kind of waiting: waiting on an answer, waiting for a return phone call, waiting for just about anything, I put it in what I call my "Wait Bin". I have found when I have a place for everything and get in the routine of using it, then when I get a phone call about a meeting or my boss has an urgent request, I will know to go right to my "Scheduling Bin" or "Wait Bin". It just makes my life so much easier. When my boss sees me in control, then he or she can relax and know that I will be able to look after the matter.
I have also found that having a good bring-forward system is essential so you do not miss important dates or timelines. I use my Task function in Outlook and continually set tasks and dates with reminders of what I need to do. Sometimes I refer my tasks to my special bins, for example if I am waiting for information from someone so I can complete a letter, I will put the file with my notes in my "Wait Bin" and put a task in to remind myself to check to see if I received a reply to my enquiry so I can follow up and not just let the file sit in my "Wait Bin".
I keep a handy notepad by my phone and write things down throughout the day and when I've completed that item I strike it off my list. I find this is very helpful when your boss just passes by your desk and asks you to follow up on something, call someone on their behalf or wants you to make a reservation for them. I write it down immediately as a reminder. I also bring a notepad and a pen with me when I am called into my boss's office so I can take any notes or instructions and then again once I have completed that item, I cross it off my list.
What works for me, may not work for you, but the important thing is to have some kind of system in place that will enable you to find things, and help you keep track of dates and important tasks. Also see an article I wrote on the bring-forward system for a good way to keep track of things that are coming up.