Protecting a user home folder using chmod and umask
Solution 1:
macOS by default sets the permission on the standard directories (Documents, Pictures, Music, Library etc) to 0700. If this somehow got changed you can easily run
chmod 0700 ~/{Documents,Pictures,Music,Library,Downloads,Movies}
to fix it. And of course you can use the same command to change the access rights for other directories as needed.
To also protect any dot files etc you can also run
chmod 0700 ~.
In any case you don't need to specially treat subfolders if the parent folder is already protected.