There are many files that help make your system usable, but they can build up over time. System logs, for example, keep track of usage, errors, and services running on your Mac, but unless you look at these often via an app like Console, you’ll probably not need a ton of log files taking up space on your Mac, especially if you have one with a low-volume SSD.
QuickLook cache files make your Mac feel zippy when you hit the spacebar to preview files in the Finder or Open/Save dialogs. If you can stand a bit of a wait to do this, deleting these files can save you some space as well.
Put together, you might save a decent amount of space on your hard drive, so give it a shot. Here’s how.