To make a small portion of icing (for just covering cookies and piping figurines),
Beat 1 egg white with an electric hand mixer till foamy. Add in 280g icing sugar a tablespoon at a time and beat till stiff and glossy. Soft peak royal icing is usually achieved after approximately 20 minutes. This consistency is good for coating cake tops and flooding outlined designs. Continue beating for another 15 minutes and you will get a stiffer icing mixture which holds its shape when shaken. I usually use firm peak icing to pipe designs and outlines for cookies and other intricate features.
To cover an entire 9 inch cake with all its trimmings; I would suggest 7 egg whites and 1.60 kg sifted icing sugar......did your jaw drop? *shrug* well...now you know what icing is made of! haha.
* add in flavouring essences such as vanilla/lemon as desired. Or if you would like the icing coloured, drop in a couple drops of liquid food colouring.For these particular cupcake decorations; I first piped firm peak icing onto parchment paper and left them overnight to dry. When stiff, I painted them with a sharp brush+liquer+ powdered food colouring. It's really versatile and I usually make my tiny decorative items in advance. It's useful to have a few pretty things on hand when you're in a hurry to jazz up a couple of cupcakes. There are countless things you could make out of piped icing. Let your creativity run wild!