I'm a natural slob, and if I let my tendencies and habits dictate my schedule, I'd never get anything done. Yet I somehow manage to keep bills paid, maintain a decent credit score, and remember when it's time to take my 92 year old mother to hairdresser and doctor's appointments. My schedule runs at its best, though, when I have David Allen's "Getting Things Done" system (widely known by its initials GTD) in place, as described in his book, Getting Things Done: The Art of Stress-Free Productivity.
Even though my GTD system periodically breaks down, it's always worth putting back in place, because it ensures that for at least part of the time, I'm well organized and working at my highest level of productivity. I'm in the process now of jump-starting the system after a lapse of several months.
GTD is based on a number of premises. One is that you should never depend on your memory, and that everything should be in a complete and written system, which you trust, and should be reviewed regularly. It requires a great deal of up-front work. Once you've spent a few days getting it in place, though, it's relatively simple to maintain. Every new thing which comes into your life, whether it's a piece of mail, an email, an idea for a vacation plan, or an instruction from your boss, you put it through a set of steps. The first is "capture" where you put the thing or task onto your stack. Next is "process", or figuring out the overall meaning of the item (is it junk to be discarded, or an urgent task?) . The third is "organize". This is where it actually gets put on a list for appropriate action. Then you "review" the lists periodically, and finally "do" something appropriate. Notice that I said "lists" instead of "list". The system requires the maintenance of a number of different types of todo lists. My favorite is “context lists” of things which are best done together. One might be "errands to run when I go downtown". Another might be "things to do while I have a phone and a computer". This creates more efficiency. If you have twenty minutes at your desk, and three short phone calls to make, you might as well do them while you're already in a place to get them out of the way.
GTD is an excellent system. It was so widely adopted that in many business settings if you use the initials "GTD" most of the people in the room will know what you are talking about without having to spell it out. The system isn't just geared for Type A workaholics. While it might at first glance seem like it tethers your life to a set of complicated todo lists, it actually creates a system for figuring out whether you should be doing any given activity at all. So even if you're an enthusiastic advocate of the simplicity movement, GTD helps you decide on the important things in your life, and provides a framework for getting them done.