SpaceSniffer is a nice free software to visually represent the files and folders in your computer. The whole directory structure is displayed in form of a tree, and you can visually see the complete hierarchy. The bigger the files and folders, the bigger are they displayed.
To free up space, just keep following the bigger guys to find the biggest of files and folders. You can also focus on file extensions that you know normally crowd up the drives. I usually start with audio and video files. They are the biggest culptrits most of the time. SpaceSniffer lets you filter all the files for any extension. So, this way, you can see all the audio and video files on your system, and get rid of the ones that you do not require.
The whole interface organizes everything visually, and makes it very intuitive to work. That’s really innovative.
SpaceSniffer also lets you search for all the files by giving a few characters of the filename. Like “abc” would search for all the files that have abc anywhere in the name.
SpaceSniffer is totally free, and very easy to use. Download using links at the end.