With the feisty and super defensive ones especially, I like to keep them as snug as possible until they grow a little more and get better used to the new home, start eating regularly and then get used to the big scary sky hands. Snug usually means setting them up in a tub and as boxed off as I can make it. A corner in a quiet room with minimal traffic.
You can try other types of enclosures, but try to make it as cluttered as you can. Crumpled paper, a couple extra hides and such if it has a lot of open space. Cover the glass if they're still trying to strike when they see you. If your baby is perched up high and ready to strike at any movement that comes their way? I'd set them up in a tub for a couple weeks and grow them up a little more. You can try again after. Most of mine will tolerate more open spaces when older except for my most defensive girl. She's still much happier in a tub than anywhere else.
As Boger said, give them that time to settle in and understand.