Transplant Japanese holly plants where you want your hedge to be, and space them 3 to 4 feet apart.
Prune the plants so they are wider at the base than at the top, so that the lower part of the plant will get enough sunlight.
Use pruning shears to thin out the tops of the plants. Clip off some of the smaller branches to allow more sunlight to reach the lower part of the plant.
Cut the branches back ½ to ¾ of their length in late winter if you want to rejuvenate the plants. They will be smaller but will grow fuller foliage.