Status of the doc: written after doing, not tested yet
This should only be done for errorlog, to help users debug their thing, but to avoid the IP logging on storage.
- Create logs folder: 
sudo -u $user mkdir /home/$user/logs - Remove or comment corresponding line in
/etc/apache2/sites-enabled/customsites.confand add it incustomsites-logged.conf - Reload apache2
 - Change group owner of newly created log file:
# user=<user># chown root:$user /home/$user/logs/* - Don't do that: force logs rotation once, to make it create log files with correct group:
logrotate -vf /etc/logrotate.d/apache2-userlogs(this will rotate all user-accessible accesslogs and create files with correct perms) - Delete empty rotated logs, lying in /home/$user/logs
 
The related logrotate config can be found in /etc/logrotate.d/apache2-userlogs