Be sure to check with more modern safety methods.Especially how to use a belay device.The Munter Hitch belay should be used with a screwgate karabiner.You should practice making this hitch dozens and dozens of times BEFORE you go to the cliff.Essentially,the rope should run the same way thru the karabiner in both directions,and lock under tension in both directions.
If you are seconding and the leader is not visible,when you know you are within seconds of falling off,shout to warn your leader. Don't just quietly fall off.
John Long was an elite Yosemite climber
Post edited at 17:41