Pick the plant or plants you plan to shape. Some topiary, such as those that appear to have two or more legs, may require several bushes to complete the form. Choose young plants and let them grow into the shape you want, or select mature plants to trim. In either case, the shrubs need to be healthy with plenty of greenery throughout the branches and not just on the outer ends.
Wrap a suitably sized shrubbery form around the bushes. Fasten the topiary form together using the connectors in the assembly kit, or use gardening wire.
Cut away any excess greenery that exists outside the shrubbery form. Try not to take off more than 3 inches from any one branch at a time. If you take too much off, the branch may die.
Trim the bush every three months during the growing season. Pruning encourages the plant to grow more leaves, which makes it appear fuller.