Nothing special. I read the Microsoft RDP client is the best one for Android, so just used its defaults.
What about from Ubuntu?
Just the defaults on 22.04/22.10. Have to use Wayland, though, which is still a bit of a mixed experience. The linked Reddit thread has more details.
Like, what client running on Ubuntu though? Remmina? I don't mean the RDP server setup, which is pretty self explanatory in settings. I weirdly can't make Ubuntu --> Ubuntu work, but with either host or client as a Windows machine I have no problem.