A 3-D project of Earth can be simple or complex, depending on how much time you want to spend on it. Making a sphere or oval to base your Earth project on is sometimes the easiest part. Giving the Earth model a 3-D aspect takes time and ingenuity, but is worth the effort when you view the final result.
Papier-mache is an old standard for making 3-D models. It is somewhat easy to work with, once you get the hang of it, and allows for many variations. To make a 3-D project of Earth, start with a round base and then work your papier-mache in layers around it. You can use newspaper or other paper for the inner layers, then switch to colored tissue paper for the top layer. Put in blue and light green for the oceans, and different colors for the land masses and forests, building each area up so that it has a 3-D effect.
Styrofoam is lightweight, yet sturdy, and perfect for some projects. For a 3-D project of Earth, start with a large Styrofoam ball. Look at a map and decide where to accurately place the oceans and land masses. Stick toothpicks into the Styrofoam at intervals, with some placed slightly higher for mountain ranges and forests. Use colored modeling clay and start creating your 3-D Earth. Press the clay on to the toothpicks so that it latches to the ball and allows you to form your Earth. If you use clay that is all one color, paint it afterward.
A balloon covered with papier-mache will not give you a round world – but it may give you an opportunity to show a different map. The Mercator map is the one most people are familiar with, and it is what adorns most globes. However, due to the restrictions of a round globe, the map does not accurately portray land mass sizes. The Peters map, among others, attempts to correct this using a different method of measurement and land mass shapes. A 3-D Earth project made with a balloon can more easily illustrate the alternative map projections.
A 3-D model of the Earth using digital manipulation is a project that may appeal to someone that is computer-literate. Some 3-D modeling software has a high learning curve; others are simpler to learn, but may not produce as complex a result.