Plants that are shaped by clipping into designs are called topiaries. Topiaries can be simple geometric shapes like a sphere or more complicated such as spirals. Topiaries can even be shaped into animals or objects. Small-leaved plants like boxwood hedges work well for designs. Such evergreen plants as conifers make good topiaries because the plant retains its leaves and, therefore, its shape all year long.
Choose a simple shape if you are a beginner. Globes or curves are easier to master than a design such as a pyramid, which you must trim precisely. A boxwood hedge trimmed into scallops--half circles--at the top would be a good choice.
Lay fiber board on a flat surface. Decide how big you want the scallops or half circles to be. Bigger half circles are easier to trim than smaller ones. Push a tack into a point that is in the middle but along one edge of the fiber board. Tie a string to a pencil and the other end to the tack. The length of the string determines how big the half circle will be. Mark the fiber board in a semicircle around the tack, keeping the string taut and marking the semicircle with the pencil. Cut out the half circle with a craft knife.
Attach wooden stakes to the half circle with several tacks to form a guide for trimming. You may need to cut the stakes to the appropriate height. The ends of the stakes should be sharply pointed.
Trim the sides of the hedge flat, but don't trim the top.
Push the stakes into the ground in front of the boxwood hedge as close to the freshly trimmed side as possible.
Use the fiberboard as a guide to trim the top of the boxwood. Use manual hedge clippers until you feel comfortable trimming. Electrical trimmers go much faster, so it's easy to make a mistake. Move the fiberboard along the hedge as needed for your design.