A mixture of different foliages help give your flower corsage a more natural look. I've used an assortment of silk leaves, but it is perfectly fine to use fresh greenery as well. I consider salal, leather leaf fern, variegated pittosporum, and plumosa as good choices for corsage and boutonniere work in fresh.
I usually wire each piece, taking care to cut off thick stems that can soon make your corsage stem bulky and hard to pin on after finished.
Bend the wire at the end and hook over the bottom lateral of your leaf. If it is a single leaf, lay the wire parallel to the stem and tape securely.
Use floral tape, stretching it out as you wind down the stem. If the tape is fresh, it will easily stick to itself, making a secure bond.