It’s really easy to make your own Papier Mache Paste using just household flour and water. I don’t really follow a recipe but a general rule I follow is 1 part flour to 4-5 parts water. Depending on the quantity of paste you need to make you can use anything from a coffee scoop to a cup. You’ll also need a saucepan to gently heat the paste.
The method is really similar to making a white sauce for cooking.