Currently, I'm attempting to roll a gdm + cinnamon DE, and have the 
packages installed, but configuration is going less than stellar.
Adding the entries to /etc/rc.conf doesn't seem to do much good, as I can't 
launch gdm.
Xorg is installed, and I can start that just fine.

Adding dbus and gdm to DAEMONS=() in /etc/rc.conf results in booting to a 
command line prompt, only to see an "Error in module" message after 
authenticating.
Adding them to /etc/rc.conf via enable_dbus="YES" and enable_gdm="YES"  
does nothing.

Most of the current documentation from a Google search results in countless 
references to installing with systemd, but I'm trying to avoid systemd.
(That said, it's tempting, because it looks easier.)