I have a small twist on this system, which is that I have a huge pool of tasks in a text file with headers for each day, and as I go through the day I pull out parts of tasklists and mark them "# DONE" as they are finished. Thus by the end of each day, each week, each month, I have an increasingly impressive list of accomplishment, even if the actual tasks are small 5-minute things. I don't try to hit a target number of tasks or a quality of task, I just do what's available that day.

One month in, I haven't missed a single day.