You do an opening to generate ideas. After the edit, you say an initiation. Maybe it’s a clear game, or a premise, or just a specific. No matter what, if it’s from the opening, your scene partner has a decent chance of thinking “oh, that’s something from the opening! I’m not scared”.
That’s something I wish I had understood in my first couple years of improv. It’s not just about generating ideas, it’s also about quickly getting on the same page with your scene partner. And getting rid of that fear.