I have not used a Display Manager in a long time on my main laptop. The default TTY login was enough for my needs. Thanks to a small snippet in my .profile the graphical environment is automatically started after login, giving me basically the same experience as with a Display Manager, just a bit faster.
My current installation of Parabola uses full disk encryption, which has its own password prompt during boot. Two password prompts to get to my working environment is somewhat annoying, especially considering that the login one actually does not add to security and will only ever be seen by me.
So I simply configured agetty to automatically log in my user account when a TTY is accessed. The mentioned snippet in .profile unsurprisingly still works. After entering my LUKS encryption key, the device will boot directly to the graphical environment.
All I had to do is change the value of ExecStart in /lib/systemd/system/getty@.service to the following:
-/sbin/agetty -a leon --noclear %I $TERM