Do chmod on multiple files could be hard if you only use chmod alone. You can use find command to filter files and folder and apply chmod with only one simple line.

Apply CHMOD to every folder and subfolder recursively

find clients/ -type d -print0 | xargs -0 chmod 755

Apply CHMOD to every file recursively

find clients/ -type f -print0 | xargs -0 chmod 644

The trick is -type -d and -type -f that tell to find command to only find folders and files, respectively.