Prune away dead or broken branches with a hand pruners any time of year. Windstorms, ice or snow can cause branches to snap. Cut off the dead and broken branches 1/4 to 1/2 inch above a lower branch junction, leaf or bud. Always scan the privet shrub to first remove these branches and twigs before starting other pruning to shape the shrub.
Stand back and look at the overall shape and silhouette of the privet shrub. Note any irregular branches or uneven areas on the plant that call for more trimming maintenance. Also determine what shape you want overall with the shrub. Determine now to guide your pruning if you wish to end up with a square, rounded or other form on the privet.
Begin clipping back branch end twigs with the pruning shears at the top of the privet. Cut into wood and leaves evenly to create a smooth facade on the shrub. Avoid shearing deeply into the plant into bare, more interior wood. Although regrowth from these barren twigs might occur, there's always a chance no leaves regrow and you create a bald spot.
Taper the shrub from the top down the sides to the base. A slight taper to the privet allows sunlight to reach the lowermost branches and leaves, keeping as much leaves growing and no bare, ugly branches in the shady bottoms of plants. The tapering needs to be gentle but obvious. For example, if the top of the pruned privet measures 3 feet wide, the bottom of the shrub needs to be at least 3 1/2 feet wide. If a cross-section is made of the privet, it should look like an A, not a V after proper pruning for shape.
Shake and scratch the shrub as you shear and cut twigs and leaves. This motion with your hands jostles debris to the ground rather than accumulating in the foliage. It retains a good view of the shape of the shrub and prevent debris from browning weeks later and making the privet look sickly or unattractive.
Repeat the trimming again as needed across the summer and autumn to maintain the shape desired on the privet. In regions with long growing seasons and little or no frost, a privet may grow year round. Ideally, avoid pruning within 30 days prior to the expect first fall frost date. The regrowth is tender and likely not mature enough to survive the first fall frost. Wait until after the frost to trim if needed, or until next early spring.