What are /r/MACNERD's favorite Products & Services?

From 3.5 billion Reddit comments

Specifically “Other” files include the contents of the System and Library folders (because Spotlight won’t report on them by default), non-media documents such as text files and email archives, plug-ins and extensions, media files that are tucked away inside a package (because Spotlight doesn’t look inside packages), and other file types that are mysterious to Spotlight. Use this little tool to find out what files are taking up your disk space and eliminate those you don't wish to keep: Omni disksweeper. Don't delete swap files, you wanna keep those for reasons I won't get into.

Also check for your backups. Time machine sometimes stores some large backup files on your disk even if you've selected backup to external hard drive. So consider disabling automatic backups and do it manually every week or so, then locate and delete some of the backups you don't want (not all of them). You might actually consider disabling Time Machine all together.

Finally, clear your Mail Application. You'll be surprised to know that tiny attachments can account for a few GB if accumulated over the years!

Good luck!