There are some variations on a basic sugar cookie recipe at the site below (scroll down.) You could also add lemon or orange zest to the dough & ice the cookies with lemon or an orange icing.

Here is a link that might be useful: Cookies

More on the right side of the site below.

Here is a link that might be useful: More variations

You can add....but not all at once...nuts...even peanuts, raisins, chopped dried cranberries and some grated lemon peel, M and M's...you can roll the cookie balls into chopped nuts or crushed crisp cereal...like rice krispies. You can add cinnamon, ginger and nutmeg and make spice cookies, you can make thunb prints and fill the thumb print with chocolate kisses, or jam or jelly of any sort, with butter scotch ice cream sauce, peanut butter or nutella . You can roll uncooked cookies in sprinkles of all colors....just use your imagination.
Linda C