Grab a serrated knife
Remove any decorations, toppers or non-edible items from the cake
Make one cut across the cake from one side to the other
Lay a knife flat on the top of the cake from your initial cut, then turn the knife upright to determine where to make the next cut, repeat until cake is completely sliced
Lay your cake slice face down
Using the width of the knife again - slice the cake into portions
Repeat this process until the whole cake has been sliced!