I know it's old hat to many people here, but this was my first air layer on a fig and I'm pleased it turned out well! Many thanks to the generous forum member who sent me the Ronde de Bordeaux earlier this year!
I used a water bottle cuff, ProMix HP moistened with very dilute MG, packing tape, and and a foil wrapper. I scratched the outer bark just a little with a knife. It was on for a long time, around 3 months, and could have come off after 4 weeks but I spent a month traveling and then kept putting it off to harvest the figs. There's still a few green figs on top, but it's meant to be a gift for a friend so it's past due. It's resting in the shade now.
It was sad to remove the figs, and I'll trim it shorter later. As so many others have said, layering was a lot easier than rooting a cutting, and with a much more robust result. :)