Making boutonnieres with an assortment of fresh greenery adds interest and texture to the design. You can use either mixed greens ordered from a bulk flower source or even snip leaves from household plants.
Be sure to temper the leaves by soaking in a cool water. This ensures that the leaves won't droop and wilt quickly. The leaves can be spritzed with a leaf polish later that ensures that moisture is locked in and the leaves will look glossy and clean for the wedding.
I begin by using a fresh lateral cut from a myrtle stem. Myrtle has a clean fresh scent when freshly cut and adds a nice touch to both boutonnieres and corsages.
Strip the leaves off the bottom of the stem. The goal is to keep the lower stem slender and manageable without a lot of bulk.
Place the greenery behind the rose head, edging slightly above the top of the flower.
As you can see by a lateral view, I've bent the flower slightly forward so that the greens can maintain a straight upward position when pinned to the tux lapel.
This is the advantage of using a rose pick . . . you can manipulate the stems to angle the way you want the flower head to go without snapping off the head of the bloom.