I'm becoming more convinced that regardless of the situation, the first thing should be to move the cyclic aft (at the same time as lowering the collective).
The few scenarios where this is not the best thing to do are pretty small - I can think of only a few - like at 40 knots or slower and less than 100 feet above the ground; (please feel free to add to the list).
Nearly anywhere else, it's a very good thing to do. There are way too many examples of helicopters hitting the ground with little or no rotor RPM, because the pilot tried to get airspeed but had no rotor RPM for control.
Remember that real engine failures have a huge element of surprise about them - way different than practice ones.