Selective pruning: If your goal is to control the size of a shrub, balance its shape, remove dead or damaged wood, or open it up a bit, take it branch by branch. Using clean, sharp bypass pruners, cut just above the place where one stem branches off from another. Pause often and step back to consider the effect of your pruning so far and whether you’ve done enough.
Renewal pruning: If a shrub is thickly overgrown, you can clear it out and renew its vigor in stages. Each year, cut out some of the oldest, thickest branches down to the ground, removing about a third of the plant. In spring new stems will sprout and in three years the whole plant will be renewed.
Rejuvenation pruning: If a bush has become dauntingly huge and dense, drastic action may be called for. Most deciduous shrubs can be entirely cut back to within an inch or two of the ground in late winter. New growth will start in spring and in a couple of years the shrub will be back at a good size. Then you can keep it under control with regular selective pruning.