Once the flowers are made and the cakes are covered the whole thing can be assembled. Even if you are transporting the cake to another venue and assembling it there, it is best to do a dry run first to check how everything will look. Start by wrapping a length of ribbon around the edge of the board and the bottom of each tier. Secure the ribbon to the board with a couple of pins, and to thecakle with some edible glue or royal icing. This instantly neatens up any dodgy edges.
Once the marzipan is draped over the cake, gently pull down the sides to cover any gaps. Smooth the flat of your hand down the sides, pressing the marzipan to the cake and amoothing out any creases or overlaps, Rub the flat of your hand or a cake smoother over the top firmly to flatten and smooth the surface. Smooth out the sides in the same way. Trim off any excess marzipan around the bottom of the cake with a sharp knife and peel it off the board. This can be kept in an airtight bag or container for use next time.