Select a pot carefully, considering what shape and size topiary you are aiming to design. The pot should complement the form in size and color.
Choose a shrub for your topiary. Since you will be making a topiary in a pot, it's easier to start with a small shrub you can form as it grows.
Construct a frame in the shape you are sculpting over the plant to help guide you when you sculpt the topiary. You can buys forms pre-made or build your own out of wire or wood.
Envision the result you are aiming for before you start cutting.
Prune small amounts with the pruning shears from a young plant. Trim no more than 1 inch from the plant in the areas that need to be shaped and filled in. Pruning encourages new growth.
Use a hedge trimmer to trim no more than 3 inches from larger shrubs for areas that need to be cut back.
Prune the plant a little bit at a time, every three months during the active growth periods. Repeat pruning repeatedly to help the plant maintain its shape and keep stray sprigs from interfering with its sculpted shape.