Mental model that works for me is that of Self-Organization (from cybernetics and complexity theory). Use interactions to enforce redundancy of potential command(See McCulloch). This way you still retain the agency as the command is initiated by you, but the emergence of order(i.e., the execution of that task in our case) can be orchestrated by changing the nature of interaction. One example would be to decentralise the decision making process when you sense the beginning of dissolution of willpower: commitment contracts(eg. beeminder), substitute activity(eg. using stairs to compensate for lack of exercise), automating tasks that can be automated, fractal attention(eg. picking up a different book when you are bored with the book, instead of stopping reading altogether) etc.
Mental model that works for me is that of Self-Organization (from cybernetics and complexity theory). Use interactions to enforce redundancy of potential command(See McCulloch). This way you still retain the agency as the command is initiated by you, but the emergence of order(i.e., the execution of that task in our case) can be orchestrated by changing the nature of interaction. One example would be to decentralise the decision making process when you sense the beginning of dissolution of willpower: commitment contracts(eg. beeminder), substitute activity(eg. using stairs to compensate for lack of exercise), automating tasks that can be automated, fractal attention(eg. picking up a different book when you are bored with the book, instead of stopping reading altogether) etc.