ILM;Repositories and Snapshots Best Practices

Hey All,
Generally asking, I would like to know what are your ways to manage indices?
Specifically, what kind of repositories do you create? What kind of snapshots?
For example, do you split by index type? By date? By size? Any other logic?

Looking for best practices advice on how to manage index life cycle and their snapshots.

Thank you!
:airplane: