I stumbled across this interesting article yesterday morning while watching an ASAP science vid on youtube. It offers a practical way of staying productive and gaining some discipline based off of the Ultradian Rhythm which is 90 mins of work followed by 15 to 20 mins of rest. This rhythm follows our natural energy cycles according to Peretz Lavie and an accountability chart could be made using this. For instance: set a time for a task (9:00 to 10:30) and then write what you have achieved after the allotted time has passed. After this rest for 20 mins and repeat the cycle with a new aim or a continuance of the previous task. It seems this is how top class violinists become so well at playing their instruments rather than the conventional way of hours of straight work with no rest.
http://www.sparringmind.com/productivity-science/
http://www.sparringmind.com/productivity-science/