Do enclose a business card or company letterhead with your media. This, along with your tracking number assigned to your job, helps us to quickly identify the media and contact the appropriate personnel regarding the status of the data recovery in house. They can overwite existing data files. If you happen to run any utility, make sure you can UNDO any alterations if they prove unsuccessful. Don't read backup tapes without write protecting first.
Many users overwrite or format tapes when they accidentally type in the wrong command.
Don't forget to verify a backup once the backup process is complete. Even a low level format can cause problems if you are not sure what is initially wrong with your device. Heads can break and the storage properties of the platter surface will be destroyed making it less likely that a successful recovery can occur.