I used to use DiskInventory X. Actually we don't need it.
- From the Apple menu, select About this Mac
- From the overview window, select the Storage page
- From the Storage page, click on the Manage... button
- On the left section, click on Documents
- At this point you will be able to see the biggest files (not the folders).
- Feel free to select any of them and click on the Show in Finder to retrieve its location
- Now, if you click on the top button File Browser, the you retrieve your folders listed from the biggest file/folder to the smallest. Feel fee o select one of the biggest to retrieve which file/folder in the folder consumes the most of space. And so on...