Accept randomness
Also 'yes, and' randomness. Expand your circle of expectation to contain weirdness.
As improvisers, we tend to set our scenes in familiar, real-life environments. But it's important to remain open to departing from reality, while still considering the concept of the Absurd Circle.
Keith Johnstone once crafted a (scripted) play where the main character preserved his sperm for future use, accidentally lost one seed in the castle moat, and chased after it as it grew into a whale-sized creature, ending up in a battle with his master.
Why don't we dare to improvise such extraordinary scenarios?