I wanted to remote desktop from a Debian machine to another Debian machine. Both have Xorg installed, i.e. the target is not a headless server.
Installed xrdp on the target (server) side:sudo apt install xrdp
Installed xfreerdp on the client side:sudo apt install freerdp2-x11
Run xfreerdp to connect to xrdp (my target hostname is “basement”):xfreerdp /v:basement +glyph-cache /f
The “+glyph-cache” is a workaround for https://github.com/neutrinolabs/xrdp/issues/1266. The “/f” is for fullscreen.
Further reading: https://linuxize.com/post/how-to-install-xrdp-on-debian-10/
Oleander Donovan's IT blog 
As an alternative, I also installed x2goserver and x2goclient on Debian 10. So far it’s hard to tell how it compares to the x/rdp approach. See https://www.google.com/search?q=x2go+vs+xrdp for more.