Place the powdered sugar and meringue powder in a mixing bowl.

Stir the dry ingredients to break up any lumps.

Add the warm water to the bowl.

Turn the mixer to low and begin blending.

Continue mixing until the ingredients come together smoothly.

Increase the speed slightly once the mixture thickens.

Mix until soft peaks form.

Add the vanilla extract or lemon juice.

Blend again until the icing looks glossy and smooth.

Check the consistency to determine if it needs thickening or thinning.

Divide the icing into separate bowls if adding colors.

Stir gel food coloring into each portion until evenly blended.

Add water one drop at a time if a thinner consistency is needed.

Mix thoroughly after each drop of water.

Fill piping bags or squeeze bottles with the icing.

Use thick icing to outline cookies.

Thin the icing slightly for flooding.

Apply flooding icing within the outlined areas.

Spread gently with a tool or toothpick if needed.

Allow the cookies to dry uncovered for several hours.

Add decorative details only after the first layer has dried.

Let the cookies dry completely before stacking or storing.