A boutonniere is as integral a part of the groom's formalwear as the bouquet is of the bride's. Although most grooms favor a flower for their boutonniere, Martha Stewart Living assistant weddings editor Livia Cetti says there are no ironclad principles on the matter.
Sprigs of herbs like rosemary and other greenery such as euonymus, boxwood, seeded eucalyptus, and geranium leaves are all possibilities. Cut the stems about 2 inches long and hold them together. Wrap them with floral wire from top to bottom, and then wrap with floral tape. Finish by wrapping a ribbon around the stem and secure it in back with a small straight pin. If you're working with delicate flora like geranium leaves, insert a wire through the base of the leaf from front to back, folding its ends back against the stem for extra stability before wrapping with tape and ribbon.
You can experiment with different leaves, wrapping styles, and embellishments. For euonymus, create a bow by cinching a piece of velvet ribbon in the center with a 6-inch piece of wire. Cover the cinched portion with matching thin ribbon, and then wrap the stem with another length of thin ribbon. Twist the ends of the wire around the top of the stem, and trim. For boxwood, wrap the stem with a piece of ribbon, and tie another to the top with a simple knot. Use narrow striped ribbon to wrap the stem of a seeded eucalyptus. Embellish a sprig of rosemary by wrapping the stem in velvet ribbon, tying a ribbon bow at the top of the stem, and cutting the bow's loops on a diagonal. Wrap the secured stem of a geranium leaf with a 1-foot length of silk ribbon; then pin the center of the ribbon at the top of the stem in the back, crisscross it down the stem, and tie a knot at the bottom.