Buy better quality meat and less of it. It’s better for you, the environment, the animals, and it’ll taste better.
Hand write a letter to someone. (Bonus: you can talk about “keeping up with your correspondence”.)
Make your bed every morning.
Moan less and laugh more.
Look up nearby tourist attractions. There’s almost certainly an obscure museum, park, or gallery on your doorstep you’ve always ignored or never knew about. Visit it.
Give things away
Drive a little slower. The time saved by speeding on your commute to work is negligible but it’s costing you money and stressing you out.
Buy a book from an independent bookstore.
Pay for something you get for free. You almost certainly use Wikipedia, pay the $3 when they ask, if you read a webcomic or follow a YouTube channel back the creater on Patreon.
And, most important of all: be kind. If we’re not kind to each other then we’re all fucked.