Begin with 12 sheets of fairly sturdy, square origami paper. Avery recommends using solid-color paper when making a spinner for the first time, as the creases will be easier to see if they're not competing with distracting patterns. Use six sheets of paper to create the water-bomb bases. Fold one piece in half, and bring the opposite corners of the paper together. Unfold, and rotate the paper so the first crease is vertical to you. Fold the paper in half from corner to corner again, adding a precrease perpendicular to the first crease. Unfold the paper, and turn it over. Make another precrease: Fold the paper in half from side to side, unfold, and turn it back over to the original side. (The diagonal creases will appear as valleys, while the horizontal crease will resemble a pyramid.)
Using one finger, push down on the paper at its center. (The creases will flex gently, and the center will start to become concave.) Hold the paper between the fingers and thumb of one hand along the vertical side edge, just below the horizontal crease. Using the existing lower diagonal creases, carefully bring the two sides together until they meet the sides flattening down to lie upon the central triangular area at the paper's lower half. Squash the upper layer of the paper flat so that all the creases collapse into position, forming a pyramid. Repeat, folding six water-bomb bases in all.
Create the preliminary base with the remaining six pieces of paper: With the predominant color facing up, fold the paper in half, bringing the opposite corners together; unfold the paper. Fold the paper in half again, bringing the remaining two corners together. Unfold again, and turn the paper over. Fold the paper in half side to side in both directions, each time folding the outer edges together and unfolding.
Refold one of the creases you previously made. Hold the paper between the fingers and thumb of one hand, about halfway across each side of the paper. In an upward circular motion, bring all your fingers and thumbs together simultaneously, causing all four outer corners to meet at the top.
Flatten the model: Swing the large flap projecting upward down to one side, while swiveling the flap underneath the model across to the other side. (There should now be two flaps pointing to the left and two pointing to the right.) Repeat, making six of these preliminary bases.
Join the two bases together: Open out one of each base slightly, and allow the preliminary base to wrap around the outside of the water-bomb base, lining up the creases in the two bases. Mountain-fold each of the four corners of the preliminary base inward, over the outer raw edges of the water-bomb base, locking the sheets of paper together. Allow the water-bomb base to reform the two sheets folded as one. Repeat these steps for the remaining bases.
Form the spinner: Join any two units together by slipping the raw water-bomb point of the first unit over the raw point of the other, but underneath the raw edge created by the preliminary base. Push in all the way until the two edges of what were the preliminary bases meet. In the same manner, join the adjacent points of the first two units into similar points of a third unit, forming a triangular section in the center. Add the final units in the same manner, bearing in mind that the last unit will be the most difficult to execute.
The ancient Japanese art of origami requires little more than some paper and a bit of dexterity. As Martha's young friend Avery Sternglass demonstrates, you can easily create a whimsical spinning toy using store-bought, packaged origami papers or more unusual materials, such as newspapers, magazine pages, maps, or gift wrap. A delightful kids' project, the toy can be spun by placing its points in the center of a child's open palms and then blowing hard against the spinner's top point.