How do you communicate love and appreciation to your friends?

We asked NPR's audience to share the ways they show affection in their platonic relationships. It's a follow-up to a Life Kit episode and story we published last month about the science of making and keeping friends with psychologist and friendship expert Marisa Franco. She says simple acts of love show your friends that you genuinely care for them — and let them know it's safe to invest in your friendship.

Franco shared more than a dozen examples of how to show affection to your friends (see the graphic below). And our audience had great ideas to add too. Here's a selection of their submissions from NPR's Instagram, Facebook and Twitter accounts — and the Life Kit inbox. These responses have been edited for length and clarity.

1. Send them a thoughtful book

Many of my friends are people who like to read. I pick books that span poetry, short stories, novels or personal essays and ship them to friends who will read and think about that work deeply. That includes Rainer Maria Rilke's Letters to A Young Poet, Fenton Johnson's At the Center of All Beauty and Thomas Hitoshi Pruiskma's The Kural.

Sometimes I'll include a handwritten note about the book and why I think they'll appreciate it. When they finish reading the book, I will often ask them to deposit it in a Little Free Library or to pass it along to someone else who might enjoy it.

I feel very touched and cared for when I receive a book that someone has chosen for me. It expresses a care for my inner life and well-being. — Shin Yu Pai, Seattle, Wash.

2. Make an effort to be there

I have two dear friends who I've been close to since age 5, Mindi and Patricia. We are going to be 58 years old this year.

I make an effort to travel to see them and their children. And they make an effort to see me and my loved ones too. When my daughter graduated from college, for example, Mindi and Patricia both came to her graduation ceremony, which involved a great deal of driving on their part. Someone commented that he didn't have one friend who would have driven that many miles on his behalf, much less that of his child. — Beth Fadely

3. Surprise each other

My best friend and I go back over a decade. She just gave me sneakers with little cats all over them — just because I love cats. — Jules Hathaway

4. Tell them what you've learned from them

It's validating to tell our friends, coworkers or family what we've learned from them. This could be a skill like cooking, listening or how to be a better friend. This action tells the people in our lives that we hear them — and what they have to say is important. — Susan S.

5. Read the articles they send you

I follow up on things they've shared with me (which might involve writing myself a reminder). That means I read books, articles and links they've recommended to me, or listen to a podcast they've sent me. — Deborah Dickerson, Bristol, Vt.

6. Send random snail mail

I send my friends mail to show my love and appreciation — and not just on birthdays or holidays. It may be a handmade card or a postcard picked up on my travels or found in a thrift store. Sometimes I share a meaningful quotation or just a few words to let my friends know they are in my thoughts. I believe that this type of mail helps the recipient feel important and special — and adds a bit of unexpected sparkle to their day. — Dana Holland

7. Show up in difficult circumstances

My friend offered to come for tea at the [assisted living] facility that my parents moved to recently. It's not a pleasant place to visit, but I have to spend a lot of time there and I usually leave feeling sad and frustrated.

For this reason, I was bowled over by her offer to spend time with my parents, who were delighted by her visit. No one else in my life has offered this kind of comfort. I continue to reflect on the visit daily with a deep sense of gratitude. — Sarah Wise

8. Give the gift of time

I feel the love when someone takes the time to join me in eating our sack lunches together, take a walk or go for a quick drink after work — nothing fancy, nothing that requires hours and hours of commitment or lots of cash (although that's fun sometimes too). — Deborah Dayman, Bettendorf, Iowa

9. Ask them how they're really doing

My closest friends and I all live far from each other, so we rely on texts, postcards and random gifts to convey our love for each other.

To truly preserve intimacy [in long-distance friendships], I've learned you have to share about your life and ask about theirs. And sometimes you have to be direct because I think we all shy away from dumping too much on friends, or try to focus on the positive.

Ask them questions like: How are you really? How is your heart, mind and spirit? Especially as one gets older, life gets so full and complicated that we get accustomed to carrying a certain amount of "heart burden" — and we don't always think to share it even with our closest friends. But it still feels good to have a friend inquire, and it still feels good to share the burden with them for a bit. — Beth Weir, Denver, Colo.

Thank you to all who shared a response to this callout. For more callouts like these, stay in touch with NPR Life Kit by subscribing to our weekly newsletter.