Macintosh computers, although having different operating systems from Windows, basically operate the same way. This means that Mac computers are also prone to the same computer problems that plagues Windows-enabled workstations, although the latter is hit with much more frequency.
They are not prone to human file handling errors too, however intuitive and smooth the Mac interface is. Having a trash bin sometimes does not seem to help. So as to increase the chances of deleted files recovery, first of all, it is advised not to save any more files in your Mac. The longer you use your Mac, the slimmer the chances are of retrieving those lost files.
There are basically two major ways to recover deleted files in Mac, and these involve separate software.
1) One of these is to utilize local programs in a Mac. Apple computers that are purchased after November 2007 are installed with the Leopard operating system. One of the most important utilities of the Leopard is called the Time Machine. This local program will recover your deleted files easily. The Time Machine enables you to quickly travel back to the point when your files existed, and then once selected, they will be placed back in their original folders. It is similar to the Deep Freeze recovery programs used in Windows.
Aside from using the Time Machine, you can always turn on the Backup utility of your Mac, so that the next time you accidentally delete a file, you always have a backup for it. Another program is the File Salvage, with which you can synchronize your data and let you back-up and restore data if you lost them.
2) Another method which is also advisable is to use the third party software to recover deleted files on Mac. There are both free software and paid versions of them on the Internet, and you can download them. Most of the better ones (which you have to shell out money) have slick visuals and user interfaces, and also have more powerful algorithms that can accurately restore the files to their former state.
After downloading a program like this, install it and let it run on the directory where you previously stored those files. Before running it, make sure to specify a destination folder so that the program can dump into it whatever it has found on a particular scan. In that case, there is no need to worry about how to recover deleted files on a Mac.