Tina and The Rules
I tried to start this post with a list of the rules of improv. It turns out there are many versions. So I decided to go with my favorite SNL alum, Tina Fey. Her rules of improv come from her book Bossypants. These are much more than ideas for aficionados of improvisational comedy. They are the most valuable ideas for life lessons I have ever seen. And I read a lot of self-helpy stuff.
Here are Tina Fey's main rules of improv:
Say "Yes": Always agree and say "yes" to what your scene partner offers. This rule is about being open to new ideas and not shutting down possibilities. It helps build momentum in the scene.

Say "Yes, And...": After agreeing, add something of your own. This rule encourages participants to contribute and build on the ideas of others, making the scene more interesting and collaborative.
Make Statements: Don't ask questions or avoid making bold decisions. Instead, make solid and clear statements. This keeps the action moving and shows confidence in your choices.
There Are No Mistakes, Only Opportunities: There are no wrong choices in improv. Mistakes can lead to unexpected and creative outcomes. This rule is about embracing the unknown and using everything that happens as a chance to create something new.
Want to try? It's easy. After someone speaks, just say 'Yes!' and then add something. Their eyes will light up! I was surprised by what a gift it can be to listen to someone and then work together to build on the ideas.