System configuration

OpenRC settings

Various parameters are controlled by /etc/rc.conf. Most common tweaks include setting rc_parallel and rc_logger to YES and rc_depend_strict to NO.

Networking

Most people will do fine with NetworkManager. For static network configuration it's preferable to install netifrc and edit /etc/conf.d/net for their setup.

User permissions

You can control who has access to and control of what by assigning them to groups. A more than full permission set for the primary user is granted by the following, consider reducing it to only necessary ones:

 usermod -a -G video,audio,input,power,storage,optical,lp,scanner,dbus,adbusers,uucp,vboxusers USER

Hostname

OpenRC can set the host name either from /etc/hostname or from /etc/conf.d/hostname, with the former taking precedence. Their syntax differs somewhat:
/etc/hostname

 reallycoolhostname

/etc/conf.d/hostname

 hostname="reallycoolhostname"