The 4-ingredient recipe for getting things done

To-do lists are useful when you're trying to decide on priorities and to spur motivation to complete tasks.

(CNN)Most of us make to-do lists to keep track of all the things we need to tackle around the house, to keep our families running and to stay on top of tasks at work.

But those lists can get unwieldy. If you often find it hard to check everything off your list despite the best of intentions, welcome to the club.
Ayelet Fishbach
Ayelet Fishbach, professor at the University of Chicago's Booth School of Business, has been studying the science of motivation for her entire career, and she knows just what it takes to achieve more.
    Fishbach is the past president of the Society for the Science of Motivation, and in her debut book, "Get It Done: Surprising Lessons From the Science of Motivation," Fishbach provides a framework grounded in decades of research that can help you finally get through your weekly to-do lists.
      This interview has been edited for length and clarity.
      Katy Milkman: Are to-do lists actually useful?
      "Get It Done" offers a framework to help you get through a to-do list.
      Ayelet Fishbach: To-do lists are useful when they help you offload the mental effort of memorizing your list and negotiating priorities. Also, they're useful whenever completing one item motivates you to attend to the next one, therefore escalating motivation.
        These lists are less useful when they cost you your flexibility. You might pursue some activities only because they're on the list, even though they're low priority and completing them won't make you happy.
        In his research, University of Virginia professor Leidy Klotz has found that it's often more important to subtract, that is remove items from your list, than add new ones. Your weekend might be more restful if you skipped the zoo or the mall.
        Fishbach suggests a four-ingredient recipe so you can accomplish your goals.