Hi Jennifer,

You could build up your structures with cardboard tubes and strips/pieces of stiff card. Tape securely together with masking tape and/or wire. Cover your structures with a watered down mix of white (pva) glue to seal the cardboard, then coat with your papier mache.

Build up your layers gradually, letting each layer dry in between. Leave to thoroughly dry then paint with a couple of coats of white emulsion. You can then paint your structures.

Good luck!