The most expensive words in data recovery are "let me just try it one more time."
If a drive holds the only copy of something that matters, every additional power-on is a bet. Clicking, grinding, or a drive that will not detect: power it down and leave it down. A failing head can turn a recoverable drive into platter damage, and no software recovers a scratched platter.
What you can safely do: if the drive is detected and mostly working, copy the most important files first — not the whole disk. Do not run repair utilities on it. Do not defragment it. Do not install anything onto it. Its next hours should be boring.
What you should not do: open it. Not "be careful opening it" — do not open it at all. Hard drives are assembled in cleanrooms, and dust is the reason. The freezer trick is folklore; at best it spends your one chance.
And the thing I would most like this forum to be known for: backups make this whole category of panic optional. One copy is storage. Two is a start. Three, with one somewhere else entirely, is a plan.
So, honestly — what is your backup setup right now? And if you have ever lost data, what do you wish you had done the week before it happened?