Decide what shapes you will use for your pattern block. You could create a block out of nothing but triangles, or you could include rectangles, squares and octagons if you want. Choose the type, size and number of shapes you will use to create your pattern block.
Arrange your shapes into a particular design. You could put an octagon atop a wide triangle, add two smaller triangles on the top for ears and an additional two at the base for feet. Place a rhombus or a trapezoid along the left or right side of the triangle, and you've created a stylized puppy.
Trace the shapes on a piece of paper with your pencil. This outline is the pattern for the blocks, and they could be glued in place over the paper. To add an additional touch to this particular design you could also color it in, making sure that each shape has its own color to make the shapes used more recognizable.