Place the cake in the centre of the cake decorating machine. Place the vertical knife against the cake and rotate the turntable manually, keeping the distance between the knife and the cake even. Adjust the position of the cake if necessary. Then, move the vertical knife along the cake and the horizontal knife across the top. Turn on the cake decorating machine, set the desired speed (the recommended speed is 75-85 RPM) and use a piping bag with the cream of your choice, such as buttercream or ganache. Pipe the cream from the top outwards. The blades will remove excess cream and ensure an evenly-finished top. When the top is ready, pipe the cream along the sides, working from top to bottom. Adjust the blades to achieve sharper corners or a thinner layer of cream, depending on your preference.