Using a calendar - weekly or monthly - works very well. I don't write down a to do list. Instead I write what I completed and how long it took me to do it. Basically I'm only writing down things after I completed the task and not before. Writing down things that need to be done only creates stress. I make exceptions for major to do tasks like payments or something but for the most part I try to avoid keeping track of too many to do's. That way I'm keeping track of my productive work only. I ignore anything that wasn't productive and simply don't include it in the calendar. Highly recommend this. I have enjoyed many positive improvements in my work output with this method. It's basically 'time-blocking'.