How do I add a directory to my backup?

By adding an override to /etc/tklbam/overrides:

echo /mnt/images >> /etc/tklbam/overrides

Or on the command line:

tklbam-backup /var/www/*/logs

Make sure you understand the implications of doing this. For example, if you add a directory handled by package management this may break package management on the system you restore to.