*Use less water when mixing the meringue powder to obtain a thick, firm consistency. *Once made, add a little bit of water (about ½ tsp at a time) to obtain a softer consistency. *Once made, add more powdered sugar if you want your royal icing to be firmer. *Medium consistency is when you cut the royal icing with a knife or a toothpick and the traced line disappears after about 20 seconds. *Flooding consistency is when you cut the royal icing with a knife or a toothpick and the traced line disappears after about 10-15 seconds.