Activating systemd --user for the first time

Whenever I set up a fresh linux machine I always struggle with activating systemd --user for the first time. Here are the steps:

This is not really a TIL. In the back of my head I have know that sudo su - or sudo su - someuser is not really the correct way to switch to another user. But I never took the time to remember the correct way. I promised myself to finally remember it from now on:

• (as root) enable lingering: loginctl enable-linger $newuser
• check if UsePam yes is set in /etc/ssh/sshd_config
• (as root) echo $DBUS_SESSION_BUS_ADDRESS
• (as $newUser) add export DBUS_SESSION_BUS_ADDRESS="unix:path=/run/user/$newUID/bus" to ~/.bash_profile (copy path from the previous command and insert correct UID)
• (as $newUser) mkdir -p ~/.config/systemd/user

And lastly add the required services to .config/systemd/user, enable and run. (And remember: defaults.target is the right setting for [Install]/WantedBy because multi-user.target only exists on systems with a graphical frontend).