Clear out the clutter
Free up space on your Mac’s storage drive
Anyone who has used a Mac for more than a few weeks knows that while you might start out with a pristine storage drive with lots of free space, it doesn’t take long before you start to fill it with apps, images, music, and other files.
Given that many Macs still ship with only 128GB of storage, it’s often not long before your Mac starts to groan under the weight of all that data. The good news is that there is plenty you can do to free up storage starting with the built–in Manage storage feature. This handy tool, accessed by clicking on the Apple menu and choosing "About this Mac", then Storage > Manage will tell you what is taking up space on your drive and give you lots of tips to free it up. For example, it might suggest moving your Desktop and Documents to iCloud or deleting attachments from Messages.
Using third–party apps like Daisy Disk or GrandPerspective can help you free up storage space, too. For example, if your Mac plays host to language files for languages you don’t need or you have large caches for applications you rarely use. Cache files are useful when you use apps regularly, because they allow the app to startup more quickly. However, if you rarely use an app, they take up space on your Mac unnecessarily. Apple’s News app, for example can store several gigabytes worth of cache files on your storage drive. That’s a lot of space if you never use it.
Other sources of large files that take up space on your Mac can include user accounts for users who no longer need access to your
machine and disk images for applications already installed.
UNINSTALL AND REMOVE
Speaking of applications, if you decide to uninstall those you no longer use, you should always use the application’s own uninstaller if it has one. That will make sure you remove not just the application binary, but all of its associated files, too. If the application you want to remove doesn’t have an uninstaller, use a third–party uninstaller to remove it.
Before you start arbitrarily trashing files, you should back up your Mac. In fact, you should back it up regularly as a matter of course. For the purposes of freeing up storage space, you could just copy large files to an external drive. However, the most effective way to back up your Mac is to use Time Machine — use it with a dedicated external directly– connected drive. A hard drive is fine, you don’t need the speed benefits of solid–state storage for backing up. While Time Machine does still work with some network attached storage (NAS) drives, network connections are no longer officially supported by Apple for Time Machine.
Once you’ve set up Time Machine with an external drive, you can forget about it if the backup drive is permanently connected to your Mac. If that’s not the case, just remember to connect it regularly so Time Machine can run a backup.
Finally, if you don’t already use iCloud Photos to store your images, turn it on in Photos > Preferences > iCloud and check Optimize Mac Storage so that only low resolution versions of your photos are stored. You can still download high–res versions when you need to, but they won’t sit there taking up space.