Like some here, I use both and couldn't really tell how - I just do it. But I certainly use power to add or subtract 'energy' from the situation (too much speed or height - reduce power. Not enough of either or both, add power).
In a low-speed aircraft like the Cub / Super Cub, I think you have to use pitch to control speed and power to control sink because using the engine doesn't make much difference to speed.
QDM