Adding corn syrup to your royal icing recipe can help your 3D flowers have a softer bite. Corn syrup is used as a moistening agent and to soften or smooth texture. It prevents sugar crystallization and enhances flavor.
Comment 1. Use 1/4 cup corn syrup per 2 lbs. Less meringue powder also helps. (Darra Varlas, FB Group Cookie Business Owners)
Comment 2. Beating the royal icing a little bit more than the rest of the icing also helps. (Roshni Patolia of FB Group Cookie Business Owners)
Picture from Wal Mart web site.