Decide which element you want to use for your model from the period table of the elements from the Web Elements website. Bear in mind that the simpler atoms to make models of are near the top and the more complicated ones are closer to the bottom. You might need to choose one that has different orbitals, depending on the theory of the atom you are studying.

Design your atom model. Determine how to place the neutrons and protons in the nucleus. If you are using the planetary theory or model, the electrons go in a single ring around the nucleus. If you are using Bohr's model or refined model, you need to figure out the orbitals and which orbitals get the full number of electrons and which one gets a partial one, if you do not choose a noble gas. If you are studying wave theory, you might need to have solid orbitals around your nucleus, rather than little round bodies.

Collect your materials. You need balls for the nucleus, and possibly, for the electrons. Styrofoam balls are a popular choice, but you can use cotton balls, marbles, small balls of aluminum foil, beads or even candy. Metal coat hangers make good orbitals and sheets of aluminum foil make a good wave model of an atom.

Glue your nucleus together. Choose one color of your collected balls for neutrons and another one for protons. Make sure you have the right number of protons according to the periodic table, as well as the right number of neutrons.

Disassemble metal coat hangers and make them into rings. Tie a string to the coat hangers and glue the string to the nucleus so it hangs in the middle of the rings. Tie more string to the top of the model and hang it from the ceiling.

Attach the electrons to the orbitals. You can use glue, or tie them to the orbitals, depending on which materials you chose. If you are doing the wave theory, wrap the aluminum foil around the orbitals.