Empty the Trash
Delete large files you no longer need
Remove duplicate files
Uninstall unused apps
Delete old downloads
Clear browser cache and history
Remove email attachments
Delete old iPhone or iPad backups
Move photos and videos to external storage or cloud storage
Optimize storage in Apple menu > About This Mac > Storage
Reduce clutter in the Desktop and Documents folders
Clear system and app caches
Remove unused language files
Delete old DMG and installer files
Check and remove large hidden files
Use iCloud Drive to store files online
Restart your Mac after cleanup