This is a minefield – sometimes even for data recovery companies, but definitely for end users.
This is probably not something that we should even be discussing. Encouraging end users to recover their data is akin to suggesting a laywer perform surgery on his ingrown toenail; you stand a small chance of getting lucky, but an awful lot higher chance of making things a whole lot worse.
There are about ten recovery / forensics programs we use on a regular basis. Some are better for recovering data from FAT partitions, and others better for NTFS. Some will stream off data as it is being found, and others will scan the entire drive, build a partition or volume map, examine the data, produce all manner options, and offer you the results, at which point you can select what you wish to save.
This brings us on to the subject of D-I-Y data recovery. Simple: if you don’t care about your data, by all means try it. If all you have stored on your hard drive is video that can be downloaded again, or photographs of mushrooms, then carry on. But if your drive contains any important or sentimental data, there is always the risk you could make matters worse by trying to recover your own hard drive. If data recovery is not a financially-viable option, try to imagine what it would be like if someone took your hard drive and smashed it to bits with a hammer. If that doesn’t make you wince, then feel free. But if waiting until you can afford professional data recovery is bearable, then that is clearly the way to go.