I often explain things to people that involve a lot of command-line work and usually resort to screen-sharing with Google+ Hangouts or something similar. This is not ideal and it’s difficult to instruct someone when you can’t both affect the workspace.
There is a better way.
I knew that GNU screen allowed multi-user sessions, and I finally figured out how to share a screen session with another user. It can be tricky, as the other person can easily screw up your typing with a single keystroke, so I reccomend Voice-chatting at the same time.
Both users need to have access to a single user-account on the server (you can use sudo su)
OR you can run some special commands to allow another user access to your screen session.
sudo su user_2
script /dev/null
screen -S lets_sharescreen -rx lets_sharescreen -S lets_share
# inside the screen session
C-a :multiuser on
C-a :acladd user_2screen -r user_1/lets_share