Improv Tips
Last year I ran a quick poll on the Roleplaying Tips Discord:

Not scientific. And small sample data set.
But it, and a newsletter on the topic, garnered some great thoughts from RPT GM Lord High PigMonkey, which I’ll share out with you today (bolding, tiny text tweaks, and line breaks are my edits):

Hi Johnn,
People seem to think Improv is just making it up on the spot. This is not true. There are hours of practice with a team of people you have to trust. Just like gaming, the prep time on good improvisation theatre is an ongoing practice. I was a professional improviser for a few years. I love to improvise, it’s my strength.
Here is the biggest secret to being an Improv DM:
Never tell anyone you are an improv DM.
If you keep the game moving forward, at pace, they will never know…
And if they begin to suspect, narrow your eyes and call for a saving throw to give them something else to think about for a minute.
Most of my prep is framework. I have a general idea of where the adventure goes, what the main antagonist is doing that session, and if there are any proactive plot points that are going to show up this game.
After that, I set the scene, and my players do most of the work. They give me suggestions, though they rarely know they are doing it, and I throw new ideas into the mix as they go along to keep the story and action fresh.
I have been playing a long time so I have a bunch of one page dungeons, a few 5RD, a few physical puzzles, and enough practice I can run a “cold start game” in about the same time it takes players to make a character.
This method is not for everyone, you have to get comfortable being uncomfortable to get good at it. I personally like riding that razor’s edge of not knowing what is going to happen next.
The trick to improv is practice. You have to suck a lot before you get good at it. I suspect that is why there are few Improv DMs. It is a stressful way to learn, and the imposter syndrome is strong behind the screen.
Most players won’t notice. You get uncomfortable because you feel you are being to obvious as a DM, I promise you are not.
One last thing… “Yes, and” is a brilliant skill to move the story along. However tying into the failing forward email from a few weeks ago, “NO, but” is the most valuable skill to keep the story from grinding to a halt.

Great tips! Thanks Lord High PigMonkey.
I agree that many GMs avoid doing more improvisation. As you said, it’s uncomfortable, even scary. And you are right about it being about making stuff up on the spot, and that one can also prepare for it and develop great skill at it.
Ok everyone. I hope you try adding more improv in your next session and that these tips help.