One thing I've realized as we've gone from a group of friends to a company is that my 'to-do' list is constantly edited with items simply removed at the beginning or end of a day. I put things on there all the time thinking they're important, but once a day, I will re-assess and take certain things off so that the list does not bury itself/become meaningless. Productivity in my life seems to be a function of pragmatism and de-cluttering (both physical and mental).