Have you ever tried using 4-squares-to-the-inch graph paper to draw out your designs? Try doing this with a pencil, 6" school ruler and colored pencils....just play around with shapes, copy some from pictures of simple blocks for practice. The ability to do this will make drawing your own patterns so much easier.
The block shown in this table runner is very simple and quite common; many of my beginning students draw and sew this using the simple sections of the block below. You can make the sections any size you want by assigning a size to the graph squares. The table runner consists of the following 3 sections.
Be sure to cut the squares from which you will cut the triangles about 1.5" larger than the other 2 sections will be.
Jan in VA