The 365N/N2 has a drill for double manual which was fairly straight forward and from memory set one throttle at a certain Tq then used the other for RRPM control - when the power setting started to get high that throttle was left at the higher Tq and the other used for RRPM control.
Once on the ground the only critical drill was not to lower the collective until the yellow throttle handles had been retarded otherwise both engines would over speed!! So one would go from hero to zero in one moment!!
HF