I think OHJ's are a disaster waiting to happen when busy
Well yes they potentially are when you see the way certain pilots fly them!
Oh and by the way, it's a good idea to keep a good lookout whichever way you join!
Seriously though I think one essential point is to make sure you are in LEVEL flight (ie at circuit height) BEFORE you enter the LIVE side of the circuit. Also when you descend on the dead side do NOT descend in straight flight (ie parallel to the landing runway) - descents are safer when turning as you are continuously clearing the airspace in which you are intending to descend.
Fly Safe!