We prune tree form shrubs much like a tree — cut to a lateral branch and avoid topping. We usually avoid pruning shrubs to machine sharpened, or a crew cut flat-topped look.
Planning when to prune is a critical factor for most shrubs to encourage flowering or to reduce the likelihood of winter burn. Some cane growing shrubs do well when mature stems are thinned regularly, while others are best when removed to the ground every few years.
Usually it’s best to avoid using a gas, electric or manual shears as much as possible by the practice of target pruning. If necessary to shear, focus on cutting the new growth only.