Write an article based on this "Obtain the materials. Cut out a 1/4 section of the styrofoam base. Paint it. Make the cell parts. Add the cell parts. Make a table or key that defines each part."
Here are a few options:  You can use a styrofoam cell base. Craft or art stores and will have styrofoam balls (if making an animal cell) roughly the size of a basketball or a styrofoam rectangular cube (if making a plant cell). Cardstock can be used to form a number of cell structures, such as the Golgi apparatus or rough endoplasmic reticulum. Straws or small hoses can be used to form tube-like structures. The microtubules could be constructed out of stirring straws, while flexible straws or tubes can be used to model the smooth endoplasmic reticulum. Use beads of various sizes and shapes as other cell structures, such as mitochondria or chloroplasts. Try to keep them on an appropriate scale compared to the other structures in the model cell. Modeling clay can be used to create any structure that is difficult to replicate using preexisting materials. Paint can be used to fill in the cytoplasm and differentiate between it and the exterior of the cell. You can also paint any clay structures you have created. Measure the base and make dots at the points that equal half the length of a side. Draw lines showing where to cut. Then use an exacto knife or something similar to cut and remove a 1/4 section.  For the plant cell, do this by drawing the center line on any two adjoining sides and continue those lines all the way around until they circle back. If doing this for the animal cell, draw the lines like you were making the equator and the meridians on a globe. Paint the inside of the 1/4 section in order to help your cell parts stand out. You can also paint the outside in a different color to contrast it with the cytoplasm. Create them from the craft items listed above. The trickiest of these will be the parts that you must model out of clay. Keep these structures as simple as possible while remaining true to the basic structure you are modeling. It may be best to only make the simplest of structures out of clay and leave more complex parts--say, the smooth endoplasmic reticulum--to be replicated using tubes or some other item. Add the parts to your cell base (the styrofoam). This can be done by using hot glue, regular glue, toothpicks, pins, staples, or a number of other methods. In some cases you may also need to literally dig or carve out space in the styrofoam to fit in the parts. The Golgi apparatus and rough endoplasmic reticulum can be shaped out of cardstock using your hands. In this case, make slices into the styrofoam and slide pieces of cardstock in to form the folded shapes of these structures. After you've added your cell pieces, write up a list of what part of a cell each item corresponds to.  You'll probably need to be able to tell people about the parts of your cell later on.