[header] How to decorate a cake with whipped cream icing [title] Chill your cookware for 10-15 minutes. [step] Before you start making your icing, place a large metal bowl and the metal whisk attachments from an electric mixer into the freezer to chill. Your whipped cream frosting will come together and hold its shape much easier if your cookware is chilled. 
[substeps] If you don't have a metal bowl, it's fine to use plastic. However, it's best to use metal, as metal bowls will help insulate cold whipping cream, which makes for a more stabilized icing.