For best results, chill the dough overnight. This allows the flavors to meld and the dough to become easier to handle. Gel food coloring provides more vibrant and concentrated colors than liquid food coloring. Store decorated cookies in an airtight container at room temperature for up to 5 days. Feel free to experiment with different flavor extracts in the dough or icing, such as almond, lemon, or peppermint. If the dough becomes too soft while rolling, return it to the refrigerator for a few minutes to firm up.