Prune off half of the new growth immediately after planting the hedge. Using pruning shears allows selective cutting, and causes less damage to young plants than hedge shears. This forces the plant to branch low, and gives a good framework for future growth.
Prune off half of the previous flush of growth the first spring after planting. This should be done before the growth buds start to swell.
Repeat Step 2 the second spring the plants are in the ground.
Shape the hedge starting in the third year. Prune the plants to be widest at the base, allowing light to reach the lowest branches. This will keep the hedge full to the ground. Taper the sides in a natural rounded or slightly sloping form. The closer the shape is to the natural form of the plant, the less maintenance will be required to keep the hedge looking its best.
Trim with hedge shears in subsequent years to maintain the form and size of the hedge. Fast growing species may require trimming several times a year.