Happy Snaps
When you encounter something that makes you happy, snap a picture of it (or grab a screenshot).
Then save it to a “Happy Snaps” album on your phone.
Whenever you need a smile, scroll through your album.
Variations
Print out your favorite pictures and make a physical album (or use a photobook-making service)
Print out your favorite pictures, and display them on your wall or desk (or use a digital photo frame)
Make a Happy Snaps widget, screensaver, background, or lock screen on your digital devices
Take a “Happy Snap” for someone you know and send it to them
Source
Happiness Hacks: 100% Scientific! Curiously Effective! (2018) by Alex Palmer