Restart your Mac
Empty the Trash
Delete old iPhone or iPad backups
Remove Time Machine local snapshots
Clear Safari cache and website data
Clear app caches in Library/Caches
Delete old Mail downloads and attachments
Remove unused language files and app support files
Uninstall large unused apps
Delete old Messages attachments
Remove duplicate or unnecessary files from Downloads
Clear system logs and diagnostic files
Update macOS
Use Storage Management to review large files
Move photos, videos, and documents to external storage or cloud storage
Rebuild Spotlight index
Check for hidden files taking up space
Restart in Safe Mode and then restart normally
Use a trusted disk cleanup tool if needed