Not much! Just a couple of things to keep in mind. First, is to make sure you're using a block of cream cheese, not the spreadable stuff. It will make your frosting too thin. Then, make sure you have a smooth texture, with no lumps. If you're trying to get a thick frosting out of the piping tip, the lumps will set you back. Prior to piping, have it in the fridge for a bit to set. It's a sturdy frosting, but it's definitely not a stable one. It will melt in the heat. So, frost just before serving, or keep it in the fridge.