Fit

The concept of fit is simple yet profound. Essentially, fit is "the congruence of the requirements of a task (location, financial investment, time, etc.) with the available resources at the time."

Often people are constrained by externally controlled schedules, locations, etc., and "fit" allows us to maximize our productivity given those constraints. For example, if one encounters a gap of 15 minutes in their schedule, it is typically more efficient to complete a task that would require 15 minutes, than to complete a task that can be done in 5 minutes, or to start a task that would take 4 weeks. This concept also applies to time of the day: free time at 7am is probably less usefully applied to the goal of learning the drums, and more productively a time to read a book. Lastly, fit can be applied to location: free time at home would be used differently from free time at work, in town, etc.

Your "Do Now" is to take your to-do list, and consider what times of the day, and days of the week, would be most appropriate for their execution. Warning: if done correctly, you'll find you have tons of left-over time.