Sometimes it’s not the tasks on your to-do list that overwhelm you, it’s just sorting through them and figuring out where to start. Before you can prioritize your responsibilities and create a schedule to get everything done (using strategies like “eating the frog” or making a 1-3-5 to-do list), you have to figure out what those big tasks are and what your capacity is to tackle them. If you’re the type of person who finds it helpful to visualize these things, I like to point you to a couple of strategies that both involve imagining tasks as rocks: the “pickle jar theory” and the “big rocks theory.”

The pickle jar theory is an excellent mental exercise for anyone who thinks or processes things visually. It was coined in 2002 by Jeremy Wright, based on the idea that a pickle jar has a finite amount of contents. So does your day. There’s only so much you can do in a day, just as there’s only so much you can fit into a pickle jar.

If you think of your day as a pickle jar, imagine it filled with three things: rocks, pebbles, and sand. These represent your daily responsibilities, but as you can see, they are different sizes. You can fit more of the smaller things, like sand and pebbles, than rocks, but rocks can still take up half the jar.

To use this kind of thinking, you need to categorize the tasks of your day. Start by writing them all down, and then prioritize them using the Eisenhower Matrix, which is useful for figuring out which tasks are urgent and important, urgent and not important, not urgent but important, and not urgent and not important.