If you like, dip tops of cookies in icing; then, sprinkle with chopped nuts or colored sugar. Or, sprinkle on the decorative toppings before baking.
For a nutty cookie, stir in 1/2 cup finely ground nuts with the flour (toast nuts before grinding, if you like). For a chocolate cookie, reduce the flour to 2-1/4 cups. Add an additional 1/4 cup sugar and 1/4 cup unsweetened cocoa powder. (Add cocoa powder before you add the flour.)