Although the actual leaves shown in this bouquet are hosta, I really prefer working with aspidistra leaves instead. In my opinion, they hold up longer and have a very similar look.
If you find it necessary to shorten the leaf, you can cut it off, pleat fold the leaf at the bottom and wrap the wire from a cowee stick around the bottom for easy insertion into the wet foam.
Cowee picks absorb water, swelling up and maintain a tight hold into the wet foam.
I offset the broader leaves to the side, keeping in mind that I want to leave a good part of the steel grass collar visible.
From now on, it's simply covering up the foam with a shallow insertion of the variegated leaves before inserting the flowers into the foam.
You can see the greened in version is beautiful and ready for the insertion of the flower heads.
I do use a product by Floralife called Leafshine. This is a plant polish that helps give the greenery a nice, glossy finish. It helps cover up the spotty white residue left by hard water deposits on all fresh greenery.
Do not spray on the fresh flowers, however - you will need a product called Finishing Touch that is best suited for sealing flower petals.