Don't put too much shortening on your pan. Too much grease on the pan and the cookies spread more. Wipe the pan between batches. Better yet, use parchment paper or a baking mat.
Cookie Tip #2 The Right Oven Temperature
Cookies spread more at a lower temperature. They spread until the heat sets the cookies. Use an oven thermometer to see if the oven is really 350 degrees.
Cookie Tip #3 Cold Dough
Cold dough acts differently than warm dough. Don't let your butter melt. Refrigerate your dough between batches.