I'm not sure if this is supposed to be in decorating or in sugar work. However I am making gumpaste roses for a wedding cake. The cake that inspired the bride is this one.

I think it's pretty but I think that a few filler flowers might make it even more beautiful.   It feels a little two-dimensional to me.   Besides babies breath which I know the bride will not want what kind of filler flowers would go with these roses?

Hello! White Hydrangeas are a classic filler flower and really easy to make, also they are quite big so you won't need to make many.

I also love using tiny rosebuds to fill, and simpler blossoms such as apple blossoms or the simple 5-petal flower with a royal icing pearl in the center.

I'm also a big fan of leaves as filler material - if you can find a way to integrate them in your design! :)