I love the variegated patterns on real foliage. Keep these leaves in tight and close. Your spray rose heads are small and going to be clustered for more emphasis. Be sure that your leaves do not overpower the armature created by the steel grass.
Although the leaves are inserted into the bouquet holder foam, the stems are very short. I dipped a corsage pin in the tube of floral adhesive and pinned at the base of each leaf to be sure they don't fall out.
You can accomplish the same thing by using wooden Cowee picks, attaching the picks to the bottom of the leaf. Twist the around the bottom of the leaf.
Here you can see I used corsage pins to keep the leaves in place.
Here's a side view of the bouquet. You'll eventually want to cover up any signs of the foam head with leaves, flowers or hypericum berries. Just make sure your mechanics are covered up.
I continued adding leaves, circling inwards towards the center of the bouquet.
You can see the inner foam becoming nicely camouflaged.