Adding power immediately after reducing the angle of attack
This is contentious, and has been argued other places
before. Before you add power, I might advice that you
get the yawing and rolling over with, and allow the airspeed
to build, just a little.
Why? Well, at very slow speeds, power can cause more
trouble than it's worth - slipstream, torque, etc. They all
can cause bad things to happen - I call it the "tail wagging
the dog". Get some airspeed, which increases the effectiveness
of the flight controls, before you add power to the mix.
I have done thousands of hammerheads in my life, and I
long ago learned that by pulling the power after the pivot,
and simply allowing the nose to fall, you not only get a
tighter pivot, but you aren't fighting the propellor at slow
speeds, and things are much less likely to go wrong (eg
hammerspin). You wouldn't believe how few people
know this.
re: falling leaf: You don't have to teach this. It's just a
shame, if you don't, after a student has been taught slow
flight and stalls. It really improves their rudder skills,
which is essential for tailwheel flying, and even improves
their takeoffs and landings in nosewheel airplanes, esp
under less than perfect conditions. It also vastly improves
their confidence wrt slow flight and stalls. Most pilots,
esp low-time pilots, are terrified of stalls. The falling leaf
forces you to get to know the stall, and to learn to control
the airplane through it. You might consider that overkill,
and that's ok. 99% of instructors, except cranky old
bastards like . and Barney and me, agree with you.
PS Slips are good, skids are bad.
Slips (when the ball falls to the INSIDE of the turn) are
harmless, and a temporary source of drag. Caused by
excessive bank (love it) and top rudder.
Skids (when the ball zips to the OUTSIDE of the turn)
are dangerous, and may cause the inside wing to stall
on you, which can see you inverted at 500 feet in a spin.
Caused by not enough bank and excessive bottom
rudder.