Instead of looping the next blades of Lily grass, I'm going to take advantage of that lovely long line to use as part of the bouquet's waterfall cascade.
If the grass is too long, snip off at the white root end, leaving the natural point of the blade intact.
Cut the stiff blade into a point and insert the single blade deep into the foam holder.
You actually can create a long, sweeping effect with the grass. I angled it slightly to the right so you can still see some of the Italian Ruscus and salal at the bottom. It's not about covering up your design elements, but rather blending them.
I always order several bunches of leather leaf fern. It's cheap and a great filler if you run short of greens. Notice how these short fern laterals are standing almost straight up.
The greened in bouquet has pleasing, blended mixture of greens in different shapes and sizes.
I wanted a little pop of change in the center focal point, so I added in the variegated pittosporum in a short, straight out lateral.