Use Diamond Plastic Ribbon to decorate cakes 

Measure your piece, then grab your small bowl with the tiny piece of fondant in it. It’s time to make a fondant paste! This is a fast and easy way to glue your ribbon to fondant, and you will have a perfect color match.

Note: Alternatively, you can use royal icing or sugar glue to stick your ribbon in place. If you are placing your ribbon on a colored fondant cake, make sure to use that same color to make the paste. That way, no one will be able to see where you have attached the ribbon.

Add a few drops of water to your fondant ball and mush it up using a spoon, a paintbrush, or your clean hands, until it turns into a sticky paste. Use a paintbrush to apply a small amount of the paste onto the cake where you want to attach the ribbon.  You can brush a thin layer of it all around the cake or just in inconspicuous places—it really depends on what your final cake will look like. Place your ribbon on the cake and voilà! You now have a beautiful cake full of bling.