Place the cluster of salal leaves against the back, behind the two lily blades of grass. This will help keep the lily grass in place and push them upright, keeping the grass from bending backwards in an awkward angle away from the head of the rose.
Again, fold the leaves around the rose head, taping securely into place. Always think of the greenery as nestling against the flower, enfolding it as a compliment rather than splaying haphazardly around the flower with no control.
Pull the tape taut as you wind it around the stem, so the tape will cling to itself.
Tape on down the rose stem.
The effect should be the leaves peeking around the rose, framing it with greenery.