>> Create a screen session (labelled)
screen -R 'myscreen'

>> Detach screen
ctrl+A (hold them) + D

>> Check current screen sessions
screen -ls

>>Re-attach screen session
screen -r <screen name, from screen -ls including the PID>
e.g. screen -r 4238.myscreen

>> Quit session
screen -X -S [session # you want to kill] quit


=======================================

>> When it gets badly stuck

screen -ls | grep pts | cut -d. -f1 | awk '{print $1}' | xargs kill 
screen -ls | grep Attached | cut -d. -f1 | awk '{print $1}' | xargs kill 

ref: http://askubuntu.com/questions/356006/kill-a-screen-session