Yes, and...

Tip #15 for shattering writer's block

A fundamental concept in improv theater is to accept whatever premise is offered by your scene partners — “yes” — then offer something of your own that builds upon the premise — “and…”. Try this with your work. Don’t judge, don’t question, just write down the first idea that pops into your head. Then respond to that and write the next thing. And the next thing after that.

This tip is from 19 Tricks to Shatter Writer’s Block. If you missed any of the previous tips, you can find them all in the Hack Your Noodle section of Read Write Repeat.