These are some of the basic things I do when I setup a new server
Get the latest directadmin.conf values
With each version of DirectAdmin, new configuration values are introduced that you may not know about. To see ALL these values do the following:
/usr/local/directadmin/directadmin c | sort -n
You can essentially copy/paste the entire results into your /usr/local/directadmin/conf/directadmin.conf replacing anything else in there.
Setup DirectAdmin with an SSL certificate
If you don't own a certificate, you can create your own with letsencrypt.com: