(Sorry I don't have pictures for this section, I hope the instructions suffice!)
For your first step, turn your fabric inside out and line up the edges (HOT DOG-STYLE! You remember hearing that term in elementary school...) so that they are all even. If you are working with scrap fabric (you little green thumb, you!) make sure that they're lined up enough so that the fabric won't look misshapen. After all that is said and done, use some pins so that it holds the fabric together.
Secondly, only sew THREE SIDES (the two longer sides and one of the ends) of your fabric together, cut the thread and turn your fabric outside-in so that your intended pattern is seen.
Lastly, fill in your pillow 3/4 of the way and make sure that it is not a lumpy pillow -- no one wants to dream of drowning in a pool of mashed potatoes (at least I hope not)!