Practice restoring a backup into a spare directory

Pick a small directory whose contents you know. Restore it to a separate destination and compare file contents, permissions and symlinks with the original.

Open one restored file using the same program that normally reads it. If the application reads several related files, restore them together and make a read-only request against the test copy.

Record the snapshot date, how long the restore took and anything you had to supply by hand. Keep that note with the backup instructions.