|image from: Buttonbag Sockpuppets|
The rituals used to create a spell puppet is very similar to that of a scroll or a wand. The spell is imbued into the puppet where it can then be recast simply by slipping the puppet over the hand and recieiting the incantion. The advantage that was discovered in using puppets rather than a scroll or a wand, is that by creating a ritual with the puppet; by moving it in a certain way and/or by recieting the spell in a different voice, the power of the spell can be augmented without added penalty or danger to the caster.
Experienced muppetomancers can even imbue multiple spells into a single puppets. Some of the more famous puppets even begin to take on, if not a true sentience, then some eldrich version of intellience.