About 5 minutes before removing the pumpkin balls from the refrigerator, place melting chocolate and shortening in a bowl. (Some melting chocolate does not require shortening for success, so depending on the type you buy, if it doesn't say to add shortening during melting, then leave it out. If you're not sure, melt the chocolate without it and if it seems too thick, then add about a teaspoon of shortening, stir it into the melted chocolate until the shortening is melted/incorporated.) Microwave at 50 percent at 30-second intervals until melted and smooth, stirring after each interval. Cool slightly. If using two types of chocolate, repeat with second bowl. (See recipe notes for further optional instructions.)
Remove pumpkin balls from the refrigerator. Using a fork, dip balls into the chocolate mixture, allowing excess chocolate to drip back into bowl. Place the dipped balls back onto the prepared baking sheet. Immediately sprinkle with salt or sugar; whatever decoration you're adding, if any.
Continue with all the pumpkin balls, then return completed truffles to refrigerator to chill overnight before serving.
Pumpkin truffles can be placed in cellophane bags, little candy boxes or small paper or foil candy cups.
Truffles keep in the refrigerator for at least a week or may be frozen for 2 months. Caution; frozen dark chocolate truffles may develop a white film that may not come off after returning to refrigerator.
Truffles are excellent when served chilled.