I don't really know of a document. I think best practice is basically how you would use them in code. They really aren't necessary unless you know of a specific area where an exception could occur.

Unless you want to take action at a specific point in the automation in the event of an exception, you might just want to wrap the entire process. The easiest way to do that is from the outer-most automation. I would start there rather than having too many inside your automations.