As we round the corner into a new year, we start thinking about what we want to be different. I’m all for dreaming big and getting more of what you want—and in fact, people who explicitly make resolutions are 10 times more likely to attain their goals than people who don’t! But making an unmanageable list of things to achieve does not necessarily make you feel better about your life; it just gives you new stuff to do.

The problem with standard-issue resolutions is that they often demand big sweeping promises, such as, “I’m going to get up at 6:00 am for bootcamp every single day and lose 20 pounds!” Great goal, but what happens the one day you don’t do it? You start down the slippery slope of “Well, I didn’t do it yesterday, so why bother?” That’s the challenge with most resolutions. (It’s also why most people don’t last past the first month.)

What if you could actually do something that changes your life now? You can. By cultivating a gratitude practice, you can make a profound difference in how you feel starting today.

Sure, you’ve heard a lot about gratitude, and certainly Oprah has done more than her share of advocating for it. But just because we know about something doesn’t mean we do it. Saying “eat kale” over and over doesn’t have much of an effect on your health unless you do it, right? Same with strengthening your sense of gratitude—it’s a muscle that you must flex to reap the benefits of.

And those benefits are manifold. Gratitude has been shown to reduce the negative effects of stress, improve sleep, and cultivate positive emotions (here’s some research to prove it).

This year, make a resolution that is both easy and fun and take our 21-day gratitude challenge.

Here’s how it goes:

1. Open a notebook, grab a post-it, whatever you prefer, and a pen.

2. Write down 3 things you’re grateful for. As you write them, give yourself a moment to really focus on each thing, like you’re savoring something delicious. They can be super simple—and nothing is too small. For example: 1. Favorite coffee this AM 2. Easy commute home 3. Funny chat with my brother

3. Tomorrow, do it again. But you can’t list your family members by name over and over and call it a day. You have to write different things—this is how you learn to flex your gratitude muscle.

4. Every day, review the list from the day before. And at the end of the week, read them all. It’s guaranteed to make you think of your week differently. Ask yourself, how do you feel when you review all these lists? Pretty good, I bet!

5. Do it again.

6. And again. For 21 days.

Why 21 days? Because some experts believe that’s what it takes to establish a new habit. Also, could it get any easier? Even during hard times or difficult weeks, there is always, always something you can point to and say, I am grateful for this. “The weather was so beautiful,” or “I love working with Joanne,” or “This is the best pasta I’ve ever had.” The small things may seem small, but together they create meaning; they make you feel more fulfilled and positive. And they add up to something very big indeed.

Terri Trespicio is a New York–based lifestyle writer. For nearly a decade, she served as a senior editor and radio host at Martha Stewart Living Omnimedia. Her work has appeared in Jezebel, XOJane, Marie Claire, Prevention, MindBodyGreen, and DailyWorth. Find her on Twitter @TerriT