If you tend to get new iOS devices fairly regularly, you may have unnecessary device backups stored on your computer via iTunes. How to delete old device backups in iTunes

If you want to save a file from the Downloads folder but don't want it clogging your drive, consider moving it to an external hard drive or flash drive, or uploading it to an online storage option like Dropbox.

Select the Apple Menu icon in the upper left corner of the screen.Click on your desktop or the Finder icon from the Dock.If you are concerned with how much storage space you have remaining on your Mac computer, you can check its usage folder to see how much space each category is taking up, including Other. How to check your storage space on your Mac Though your Other storage might have been spread out across categories in macOS Sierra and higher, you can still follow the below steps to manually clean up your Mac and get rid of unnecessary files. Purgeable files also include caches and temporary files that used to fit into the Other category, which will also be deleted as your hard drive starts to fill up. The Purgeable files are what Optimized Storage will move to iCloud and delete from your hard drive only if your hard drive starts to get full. Older documents are stored in iCloud, while a shortcut icon is kept on your Mac (files are automatically re-downloaded to your Mac as soon as you open them). When you move your Documents into iCloud (part of the Store in iCloud component) and your hard drive gets low on storage, only recently opened files are kept on your Mac. This is part of Apple's Optimized Storage service.

If you check your system storage graph in macOS, you'll probably discover a category called Purgeable.

How to clear other space on mac