Line a large baking pan with parchment paper or a silicone baking mat. Set aside.
Place chocolate or chocolate chips in a microwave-safe bowl or dish; microwave on high for 30 second intervals, stirring each time. Once most of the chocolate is melted, allow the residual heat to melt the remainder of the chocolate, stirring until it is smooth -- do not overheat. (See Notes below for instructions on how to use the double broiler method.)
Add ½ teaspoon shortening at a time if needed to thin out the chocolate. You may not need any at all depending on the type of chocolate you use.
Place a graham cracker in the dish, and then use a fork or small tongs to flip the cracker and coat the other side.
Carefully lift the graham cracker out of the chocolate with a fork or tongs, tapping lightly on the edge of the bowl to let any excess chocolate drip off.
Place the dipped graham cracker on the parchment or silicone-lined baking pan. While the chocolate is still wet, sprinkle with desired toppings to allow them to adhere.
Allow the chocolate to set either in the refrigerator (5-10 minutes) or at room temperature (could take several hours).
Remove the chocolate covered graham crackers from the pan and package them or store in an airtight container in the refrigerator.