Platonic Solids Models
And explore 100s more at Animated Polyhedron Models.
You can also see some Images of Polyhedra if you want.
It is best to print these model templates on cardboard or thick paper (160-210 gsm), but they can also be printed on normal paper, they just may be a bit "floppy".
If you print on normal paper you could then glue them onto a sheet of cardboard, or just use the paper template as a guide for cutting the cardboard.
After cutting out the shapes you need to fold neatly along the dashed lines. To make folding easier and the final product more professional-looking, you can score along the lines before folding. This means to carefully scratch along the line with a knife, nail or similar object (use a ruler to keep the line straight), just don't cut through!
Rubber bands (not too tight!) can help hold the model together while the glue dries.
You can use good quality cardboard for the job, or just cut up some cardboard boxes from the kitchen (ask first!). If you use cardboard boxes, then it might look better if you paint the inside and show that on the outside of the model.
Finally you can color in each side in fashionable colors, or you could glue on pictures or designs from magazines, and you could even attach string and make a mobile!
If anyone has photos of some models they have done, just let us know, and we can feature them here.