Pruning method for Pine - This type is to be trimmed during its active growing season. That will give it time to grow new buds for next year. You can use hand pruners or simply break off the branches at the desired length.
Pruning method for Arborvitae, Juniper and Chamaecyparis - These three types of conifers should be pruned on new growth only because they do not grow on old wood. You can safely trim where you see pliable green stems. If you remove brown and old stems, new ones won’t grow back. The reason to trim these trees is for size control.
Pruning method for Fir, Douglas fir and Spruce - These types are usually cut to control their height. You should prune them during their dormant state. Make a cut half an inch above the buds and it will become the new leader when the growing season begins.
Pruning method for Hemlock and Yew - The best time to trim these conifers is either in late summer or late winter. After pruning, they get a growth spurt, so it shouldn’t be done when they are actively growing. Furthermore, lightly trimming these types of trees will encourage their fullness.