Istio documentation covers many scenarios how you can start up Istio and get your hands dirty with its offerings. Things become a bit more tricky when it involves multiple clusters, and even more complicated when there are other Open Source projects you need to deal with.
The presentation will be mainly driven by demos. The first demo will be based on simply starting multiple KinD clusters locally, and get Istio offerings in action.
The second demo will be based on GitOps setup with the similar multiple local clusters. This will involve some UI examples to showcase Istio offerings similar to bookinfo example, and backed by GitOps.
Lastly, there will be a short demo with multicloud + multicluster + GitOps setup, which gives the sense of how you can get production ready multicluster setup with Istio.
All the demo steps are documented in GitHub repo, and every step for each demo is curated to get the clusters up and running from scratch.