Watch this video from This Old House to learn how to prune a privet hedge.
1 Use loppers to remove one-third of the older stems, so sunlight can penetrate the hedge's interior.
2 Find long stems that grow out of hedge, and snip them close to the ground.
3 Where one stem branches into two, cut just above the Y-shaped split.
4 Continue cutting older stems, but leave new growth.
5 Use hand pruners to thin stems.
6 Place clippings in trash bags.
7 Next spring, apply a shrub fertilizer.
8 Next summer, repeat pruning by removing one-third of the large stems.