I enjoy "hand" feeding using bamboo skewers. I leave my panthers in their cages, and let b. dubia nymphs crawl on the skewer. My hand is about a foot from the chameleon while holding the skewer. It's great for letting newly acquired and timid chameleons eat in close proximity to you. Also you know exactly how much they are eating, and not run the risks associated with free roaming insects.
Just make sure that the skewer is not splintery, and don't feed from the pointy end.