What the horse and buggy are to cars, handwritten notes are to texts, right? Well, not exactly. A personal note is a timeless classic that never goes out of style. More than that, research shows that the act of writing down our thoughts and feelings can boost mental clarity and increase our sense of gratitude. Journaling is one way to get these benefits, but writing gratitude letters to others can have an exponential effect.

Sounds pretty easy. So, what keeps us from sending notes of gratitude more often? According to Amit Kumar, co-author of the study, it’s often because we try to anticipate how our note will be received. We worry about our wording, if we expressed our thoughts well, or sounded silly.

That hesitation can keep us from writing the note at all. According to Kumar, as writers we can “overestimate how awkward recipients would feel, and underestimate how positive recipients would feel.” In other words, we misjudge the value of the action – such as expressing gratitude – and it keeps both parties from getting the mood boost.

In an interview on the topic in Time, Kumar says, “If both parties are benefitting from this, I think that’s the type of action we should be pursuing more often in our everyday lives.” As long as your expression is genuine, warm, and from the heart, the receiver will have a very positive reaction to those intentions, Kumar says.

The key is not to overthink it. To make it easier to follow through, he suggests keeping cards on hand, so you can compose a note whenever the mood strikes.

Need a little guidance? The New York Times writer Gina Hamadey interviewed a number of experts on the subject of writing gratitude letters, including Kumar. Advice was plentiful and helpfully specific.

The first step is to decide on a recipient. It could be your best friend, a valued colleague, or a beloved relative. Nancy Davis Kho documented her year of writing gratitude letters in, The Thank-you Project. She suggests thinking of the five people you most wanted to hug when COVID restrictions relaxed. Ta-da! You have a list.

Now, gather supplies, such as stationery, cards, and your favorite pen. “Handwritten letters are the gold standard because your handwriting is an extension of you. It’s personal and tactile,” says Hamadey. Don’t get hung up on penmanship. No one is expecting calligraphy. Typing your note is fine. The goal, she says, is to create a meaningful object that will arrive as a surprise. It may even become a cherished keepsake.

Spend a moment to think about your recipient. Focus on details, like how you met, experiences you’ve shared, kindnesses bestowed. A gratitude letter isn’t meant to cover the lifespan of your relationship, just something you want to acknowledge.

Let the writing begin! Don’t worry about sentence construction or even, necessarily, grammar and spelling. Kumar notes that the person who gets your letter won’t be scrutinizing your syntax.

Finish with a flourish. This is when you should feel free to note your feelings of gratitude. You can even end with a sincere compliment. As a sign-off, you might add a “wish for the future,” a chance to continue to make happy memories together.

Davis Kho says she often takes a photo of her letters before mailing them, which is how she compiled them into her book. “When I’m feeling low, the book reminds me that I’ve done a good job selecting people,” she says, “and that there are people hidden in plain sight who make our lives better.”

Here are a few reasons why handwritten notes have such a positive effect on us.