Keeping the tank covered does wonders. Just get an opaque blanket or a few towels to do the trick. I'd try to put the frog tank in a little-travelled area of your home or building to minimize stress, also. And provede a bunch of hide spots in the tank; hollowed out logs, dried/microwaved leaves, and such. It might also be a huge unburdening of stress if you put the frogs in seperate enclosures; the leaping of one frog will definately upets the other.
I am not familiar with the exact husbandry of this species, but I have drooled over pictures of them on the 'net. Rest assured, I am very jealous!