Protecting a user home folder using chmod and umask
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.