One of the best exercises I know of on how to learn and practice User Story slicing techniques is the so called Elephant Carpaccio exercise. To help facilitate the workshop I put together these slides. You can read more about it in this Crisp.se blogpost and access the presentation here.
One of my biggest surprises when I first met the squads I where going to work with at Spotify was that none of them were using User Stories. At first I observed to see their alternative. Unfortunately there was none. I developed this workshop to try to introduce the concept. Read more and get the slides from Crisp.se
The best lean flow game there is, with extremely simple props: post-it notes and colored dots. You can run it in an hour and get tons of experiences and stuff to discuss. I have put together a presentation to make it easy to get started facilitating the Lean Dot game.