Trailing ivy is a lovely accent when you are making boutonnieres and corsages. Ivy should be soaked in a tepid bath before using in cut flower work or bouquets.
I hook a wire over the stem between the ivy laterals.
Fold down the wire and pull it down gently, making sure it is connected with the ivy stem.
Tape the wired stem with corsage tape.
I spray ivy and other fresh greens with Leafshine sealant. Florists use large cans of this, but I sell a smaller can that works very well for a single DIY wedding.
Take a critical look at the ivy and see if it compliments your design.