Create the armature of your puppet. The armature is a flexible wire "skeleton" that will allow your puppet to move and hold poses while retaining its basic structural integrity. To make the armature, form pipe cleaners into the rough outline of your puppet. Add structural support and body to the armature by twisting multiple pipe cleaners together or looping a pipe cleaner around on itself, creating depth.
Form the core of your puppet around the armature, using a neutral-colored, polymer clay. The core of your puppet is any section which will not need to articulate. Examples might be the torso of a human puppet or the beak of a bird puppet. The core does not need to be exact, but should be smaller than the desired dimensions of your finished puppet, as the core will be covered up by colored clay later in the process.
Fire the puppet's core until dry, following the polymer clay manufacturer's instructions. Most polymer clay can be fired at low-heat in your home oven. Once fired, allow the core and armature to cool completely.
Complete your puppet by forming the finishing details around the core using colored polymer clay. Add details as desired. This layer must not be baked to maintain pliability and allow for articulated movement during filming.