Once your butter is beaten, then beat in half of the sugar. Once it’s thoroughly mixed in (about 30 seconds using an electric mixer), add the rest of the sugar and beat that in, too. Now add the rest of the ingredients and beat those in for about a minute, or until the frosting looks creamy, thick, and, well, frosting-like. If it’s too runny still, add in a little more sugar. If it’s a bit too thick, add in a little more milk, until you reach the desired consistency.