We had these polystyrene separators made for tiered cakes that only require to be separated by a couple of inches. These include designs where the wedding cake has nothing but roses between tiers. Whether real, artificial or sugar roses, the wires can then be pushed into the polystyrene to fix them in place.
If the polystyrene dummy is going to be seen, wrap a wide satin ribbon around it a couple of times.
How to use: for each polystyrene dummy you will need the same size single thick card which must be stuck to the bottom of the dummy with a glue like Pritt Stick. You must insert plastic dowels into the cake underneath where the dummy will sit, these may have to be cut as they should sit level with the top of the cake. They should all be cut the size height so that the cakes sit level. I usually use 4 dowels in each cake - to make life easier you will find the cards and dowels (plastic cake separator pegs) all on this page.