On my most difficult days, like when I was managing my startup while being a stay-at-home dad, the to-do list felt more than overwhelming. It felt impossible. Along the way, I found one simple trick that would keep my sanity.

Put one thing on your to-do list. Only one thing.

Here's how it works: The night before, decide the one, and only one, thing that must absolutely be done tomorrow. If you're having a hard time figuring out your priority, you can, to paraphrase Warren Buffett, make a list of 10 priorities in order, then eliminate the bottom nine.

The next morning, concentrate on the one thing you have to get done.

For me, the results were spectacular. First, I would almost certainly get the one thing done. Second, it would get done early. Third, it would give me the confidence to go on to the next activity. Fourth, it would bypass all the stress caused by having too long of a to-do list. Lastly, I'd move through each task so fast, I would inevitably get more done than if I focused on the entire list.

As Essentialism's Greg McKeown recently said, our problem is that we put equal weight on all our to-do list goals. By having only one in your vision, it becomes absolutely clear what you must get done today.

And chances are higher that you'll get it all done.