If you arrive at your free time, without knowing exactly what you are going to do - it's pretty much gone. Your mind is very good at confusing you with the sudden freedom.
One method I have used is - I put down a calendar entry in the free time (can be reading a chapter or any of the tasks) - when the free time comes and the calendar entry is there, my mind has no option but to do it. The calendar is pretty powerful construct that way - years of conditioning to attend meetings during a calendar time, i guess.
Nice article Soha.