Do note any obvious symptoms that the drive is having.
Don’t try to guess what is wrong based on those symptoms. Many problems have similar symptoms.
Do try a different cable if your drive is not being seen on the computer.
Don’t leave a drive that is not being seen plugged into power. The drive can damage itself further.
Do try to make a backup copy of your data if the computer acts funny for any reason.
Don’t make any further attempts to get data if the drive fails. The more use a drive has after it fails, the less likely a recovery is.
Do have an IT shop confirm that the hard drive has failed.
Don’t have an IT shop attempt data recovery unless you are willing to lose the data. Someone that does not specialize in recovery cannot take the same precautions that we can.
Do package the drive carefully before shipping it to us.
Don’t forget to include your paperwork inside the box. We need to be able to contact you when we get your data back.