A xerographica (commonly referred to as Tillandsia air plants) have both interesting leaves and colors and look stunning in bridal bouquets.
I would insert a Gauge 24 or 26 florist wire in a "stitch" pattern and then carefully bend down on both sides.
Fold the two sides together and carefully tape down, creating a "stem" to insert into the bouquet holder foam.
This florist seems to skip the wire and simply folds the leaf over
pinches it tightly
and twirls the leave to create a "florist tape tail" that
she inserts into the bouquet holder. Every designer is different. I would use wire and then tape.