Stone skipping does spinning help? I have tried to hurl a stone with some added rotation and it performed slightly better but I have great difficulty replicating this feat for consistency, my question is should I add angular momentum to my throw or it was just a waste of energy? 
 A: Try thinking of your stone as a spinning top. Its angular momentum will stabilize its orientation in the air, flat side down, which in turn will make it skip  across the water more evenly. Without the angular momentum, it would topple over, just like a spinning top that has stopped spinning. That would make it hit the surface of the water with some pointy side, expose it to greater friction, lose its kinetic energy, and sink into the water sooner. 
So no, making your stone spin is not a waste of energy, as long as the energy you 'invest' into the stone's rotation does not exceed the reduced loss of kinetic energy from consistently hitting the water surface with the flat side of the stone. 
The "as long as" qualifier is, of course, partly a function of your throwing skills, which you are better-qualified to judge than I am. 
A: There are two tricks to a good skipping stone.
Lydéric Bocquet published some meaningful work on this subject.
Firstly, the spin makes sure the stone maintains its orientation just as a spinning top does.
Secondly, the orientation you want to impart to the stone should cause its trailing edge to hit the water first so that the collision will drive it back upwards due to "angle of attack" (kinda like holding your flat hand out the window of a moving car and orienting it 'trailing side down').
The spin is not wasted energy.
