You can find old seat belts from car manufacturers and thrift stores. In addition, you can purchase belts made out of seat belts to help children learn to effectively use a seat belt. Purchase one of these for each child. Let the children decorate the seat belts with embellishments such as rhinestones and glitter or permanent marker. During a seat belt safety lesson, teach the children to buckle up properly with their own personal seat belt. Emphasize that this seat belt is just for fun, but children must use the cars' seat belts when traveling.
Many cars are equipped with over-the-shoulder seat belts, which children should learn to wear properly. These seat belts shouldn't be used with one arm over the top, as many children would rather do, due to comfort. Teach children the proper way to use these seat belts by using butcher paper to cut out an over-the-shoulder seat belt for each child. The children can then decorate them and model them.
Coloring, while a simplistic craft, can also serve as an educational tool. Most school supply stores carry coloring books about safety, which often includes seat belt safety coloring pages. Copy these and give to each child to color after a lesson about seat belt safety. While the children are working on the craft, ask them what they've learned about seat belt safety. You can even include a song or a poem for the children to learn as they color.
Ask each child in the class to bring in a favorite doll or teddy bear. Purchase rope, use torn-up sheets or paper to help the children make "seat belts" for their dolls to wear in the car. You may even be able to cut up old pieces of seat belt for this craft. Help the children place the seat belt over the doll's shoulder and lap and fasten it with a simple knot or glue. Children can also decorate these to make them their own.