I'm going to go around and fill in between the already set roses. The roses I set in the back are going to face even more away from the front of the bouquet.
See how this rose points back, adding to the depth perception.
My eye is drawn to the bottom left, an open spot in the cascade.
I insert a long stemmed rose and turn the flower face to the left.
It's especially important that monochromatic bouquets (ones with all the same color - particularly ones that are all the SAME FLOWER) - careful placement of the flowers is needed to emphasize depth, in turn adding more interest.
I'll talk about a product later called Floralock. It is a canned flower adhesive that is squirted into the bouquet close to where the stems are inserted. The adhesive flows around the stems, locking them into place. I consider this especially critical for cascade bouquets.
Florists used to insert a long wire up through the bouquet, effectively wiring the cascade so it didn't fall out. You don't have to worry about that problem if you use Floralock.