i was never taught how to do it,.....just through trial and error after my own harddrive crashed back in 08'.
After i figured out how to successfully do it.....i started charging other people to recover data off their harddrives.
There are quite a few data recovery programs out there.....File Scavenger is the best to me. The program is barely 2mb
in size,....but its powerful as hell. You can even recover data from a harddrive that has been formatted. And it will recognize
an external harddrive attached to your computer even if your computer doesn't.
I've also successfully used it with SD cards from phones and tablets.
If the harddrive spins, then i can get the data off of it. If not,....then it'll probably have to go to a clean room and have
the heads replaced. However, data recovery isn't available for SSD drives.....which is why i refuse to save anything to them.