Print triangle graph paper. There are a number of places you can purchase such paper, or download it straight from the Internet.
Draw a triangle that is equal on all three sides in the middle of the paper, each side exactly nine units long. All sides being equal make this triangle equilateral.
Make another equilateral triangle in the middle of one side of the triangle you just drew. It should be three units long on all three sides. Repeat this on the other two sides of the original triangle.
Erase the bases of the three smaller triangles you drew. This makes a 12-sided star, like the Star of David.
Make 12 more triangles, one unit on each side, in the middle of all twelve-sides of the star.
Erase the bases of all 12 new triangles. Your image now resembles a snowflake.
Draw 48 new triangles, each one-third unit on each side on all 48 sides of your snowflake. As you can see, this can continue on forever, making more and more levels of the snowflake. Each time you erase the base the triangles get smaller.