Files: ls -lSh | tac
Note that tac relies on /tmp. In the event that this mount is full, try ls -lSh | head.
Directories: du -hd 1 | sort -h
Requires GNU coreutils (e.g., macOS users can run brew install coreutils).
Navigate to System Settings -> Storage.
Files and Directories: ls | select Name,@{n="Length"; e={[long](ls $_ -file -rec | measure Length -sum | % Sum)}} | sort Length -d }
Or navigate to Settings -> Storage -> Other.
Navigate to Files -> Clean.
Navigate to Settings -> General -> Storage.