Depends on what you'd like the puppet to ultimately do. There are three basic types of puppets: rod puppets, hand puppets, and marionettes. Some puppets are a combination of these (i.e. -- Kermit the frog is both a hand and rod puppet). Other easy puppets can be made from lunch bags, paper plates, and so forth. Just find something that can open and close easily and build on that. The book "Muppets Make Puppets" is a good reference.