Others in Macintosh HD How can I reduce the size of my HD folder? I have more than 22 GB in "others". 
It is actually using more memory than my documents and apps and does not show contents.
I have deleted the main info in mobileSync folder, but is still very big.
I'm a big fan of Daisy Disk. It gives you a graphical display of the usage of your drive. It lets you delete items pretty quickly too. You can try it for free. (Disclaimer: not associated with Daisy Disk except as a satisfied customer.)