Backup Architecture and frequency

What components/directories of the webmethods platform are key to back up. I have read the webmethods guides and have extracted the ones they label are core ones to back up.

However I was wondering what is ideal from others experience. I have heard some do the ones listed in the webmethods documents. I have heard other back up everything under the Root (Home} directory for each component to ensure complete capture. Please advise

Also, How frequently do most do these backups of the components. I know it will depend on the business, however practical experience numbers is what i am looking for.

Example - Full Backups once a week;Nightly Incremental backups, etc