They are delicious plain, but there are a few things you can do to decorate them.  Try rolling the dough balls in coarse sugar or granulated sugar before flattening them with the fork. This gives them a sugary, crunchy coating. You can even use colored sugar. Sprinkles would work, too. Choose a small sprinkle size and roll the balls in them before flattening them. You can also dip them in chocolate. Once the cookies are cooled, dip them in melted chocolate, or you can drizzle it over the top. You could also top the chocolate with some sprinkles before it sets.