Place the decorating tips inside the pastry bag and pour the royal icing inside each bag.

Decoration idea #1: Outline each heart cookie with the royal icing leaving a small space of about ¼ inch (6 mm) between the edge of the cookie and the icing. Fill each cookie completely with royal icing and cover the spaces with the scribe tool or toothpick. Shake gently and let it dry for several hours.

Decoration idea #2: As soon as you fill out the heart with royal icing, place several small dots on top of it with royal icing of a contrasting color. Let it dry for several hours.

Decoration idea #3: As soon as you fill out the heart with royal icing, place several small dots on the edge of the icing and around the heart. Then, drag each dot with a scribe tool or toothpick to shape each one into a small heart. Let the cookie dry for several hours.