Manufacturing a convincing creature requires several steps, but the process always begins with a basic design stage. A monster builder might develop a creature on paper or build maquettes or small models. Once these prototypes are approved, the creature builders determine whether the monster will be portrayed by a performer in a costume, a puppet, or some other effect.

When a costume is built for an actor, the mask can be augmented by cable-controlled eyes, air bladders, and other features. The actor's movements and body language are also vital to this process. Creatures that require a wide range of facial expressions may warrant a separate, cable-controlled head for close-ups.

Puppets are generally employed for extremely small or large creatures. Puppets of all sizes can be operated from below, above, or even behind the set by puppeteers. In some cases, the puppeteers are actually inside a huge costume. Larger-than-life monsters are usually small stop-motion puppets filmed on miniature sets with high-speed cameras.