Need Motivation? Schedule It

The secret to motivating yourself to do something you think will be unpleasant isn't about willpower. It's about timing. As management consultant Peter Bregman puts it:
"Never quit a diet while reading the dessert menu."
In his HBR.org post How (And When) to Motivate Yourself, Bregman says the best time to motivate yourself is not when your your motivation is low already or you are caught in the day-to-day grind. Instead, he argues, plan a time to make the decision -- decide to decide.
"Knowing you have a planned pause allows you to focus and concentrate without hesitation until the established time to second guess yourself. And if you do eventually decide to change your commitment, you'll know it's not from momentary weakness. It'll be a strategic, rational, intentional decision."
How do you motivate yourself to start on an unpleasant task?