To do lists are a must for many people. For me they have often times become less about what is really on the list and more about clearing my mind of thinking about what I have to or should do in the day or week ahead. I love to make my list before I go to bed so that I don't go to sleep running through the list while I'm trying to fall asleep. This has seemed to help me get better sleep and keep my goals on track.
I frequently find myself rewriting my to do list and either updating it or getting rid of it and starting a new one completely. More recently I've developed a small log that I have separated into sections related to areas in my life that I always seem to have things I want to accomplish. Sections are split into professional and personal categories specific to my life. If I think of something while I'm in the middle of doing something else I can quickly flip to the page in the little book and jot down my idea. This saves me time because it is already categorized and when I get a free moment I can refer to my reminder in a quick and efficient way. I also don't lose track of my goals or great creative ideas when they randomly pop into my head.
I find that keeping to do lists too long can make me feel bad about myself if I haven't accomplished something. This is why I like to revise them often and keep a separate book with more ideas than actual tasks that I feel like I must complete. Really important things that I must do that day or week I write on a single piece of scratch paper on my desk that I keep in one spot every day. After I complete the task I'll cross it off and later recycle the piece of paper, usually at the end of the day or sometimes end of the week depending on what's on the list.