One recipe for sculpting the moon
You will needUsing a projector, you may copy the contours of the topographic map of your favorite site onto a large piece of paper. The scale of the copied map depends on 1) how large you want the model, and 2) the thickness of the styrofoam plates. For example, if you use 1 cm plates, then it may be appropriate to choose a scale of 200 lunar meters per centimeter. So every 200 meter contour is then necessary to copy onto the paper. If your plate is 0.6 x 1.2 meter it will cover 12 x 24 lunar kilometers. You may scale this anyway you like, but the contour levels need to fit the thickness of the plates in multiples. For example, you may have chosen 300 meter per plate thickness instead.
Once you have copied the necessary contours onto the paper, punch holes along the contours and into the styrofoam with a pencil, and connect the dots with a feltpen. Start at the bottom plate, mark off one contour, put the next plate on top, and mark off the next contour, and so on. When you put the next plate onto the stack, fix it with pins so they dont slide sideways. Use reference corner points on the map to align it to the plates. For labelling, mark each plate with the contour level (for example 5500).
When you have copied one contour on each plate, and done all of them all they way up to the mountain peaks, you are ready to cut the plates, starting with the top one. It is a good idea to take it off the stack first. Store the cut plates systematically so that they are easy to find again when glueing.
Now, glue the plates together one by one starting with the bottom one. Be careful to place them in the right position. Use your map as a guide.
If you use 2 cm plates (or larger) one can use foam in the corners to reduce the amout of spackle. When the foam dries it will expand, so you will need to cut it with a knife to level it down to the corners of the plates.
After the glue has dried, cut off the corners of the plates, about 0.5 cm, to reduce the amount of spackle needed to fill in the corners. You may now cut so that there will be an even slope. This is also the time to cut out depressions for the larger craters.
You are now ready to put on the spackel. Use several layers if necessary, and let dry in between. As it dries, it may crack. Then fill in these cracks. At this stage it is very efficient to use a small lightsource to simulate the sun. This reveals the shadows of the landscape, and this is the time you get the lunar feel. Compare to your Apollo pictures.
Use a pea or different size pebble to press in the smaller craters in the half dried spackel. It might help to use water. Smooth out the landscape with your fingers, using spackle and lots of water. After everything has dried, use sandpaper if necessary for smoothing. Use the Apollo picures to get a feel of how it should look, and correct accordingly. Add spackle if needed.
Now comes the difficiult part, because it requires a good deal of patience to get the right look with different shades. First, mix the black and white matte paint to a relatively light greytone base color. Then you may roll on the base with a small roller. Let it dry completely. Then, use a light grey to brush lightly with very small amount of paint to bring out the small bumps. The final trick is to use a darker grey to "smudge" the landscape here and there. Use the Apollo picures to get a feel of the color, and your artistic ability!
Think about that no harm is done if you are not satified with the color the first time, so no need to stress. You can always re-paint!