How to delete old iOS software update files.How to delete old iOS device backups in iTunes.If you've ever backed up or updated an iOS device to iTunes, these two can save you gigabytes of space all on their own. If in doubt, however, move them to an external drive instead!) Old iOS device backups and software updates (Sometimes studios pull their movies or shows from iTunes, so it's a risk, but it doesn't happen often and they usually return. That lets you stream content to your Apple TV or re-download it to your iOS devices or iTunes on your Mac whenever you want. You can either transfer them up to an external drive for safe keeping or, if you're not adverse to it, simply trust in Apple's iCloud service. If you've downloaded movies or TV shows from iTunes in the past and you're done watching them, you can also get back tons of space by removing the physical copies. iOS game files can be 1-2GB as well in some cases.

A single HD TV show can take up 1GB or more (that can be 10-20+GB a season!). Large videos like movies, multiple smaller videos like TV shows or home movies, or even massive amounts of tiny files like music and apps can all add up. The most common offenders when it comes to eating up storage space are media files.

How to clean up mac hard drive space