One technique is called braining. You simply stab the skull which allows all the juicy goodness entice the snake. Just a small hole will do with a lite squeeze afterward to get just alittle fluid to come out.

You can try to feed to often and to long, both of which will add to stress. I would suggest 4 day offerings and nothing longer than 10 minutes.

I dont know the cage setup but if it is glass sided I would cover them to add to privacy. Thick paper will do. Also a cage that is to large can be an issue . GTP babies are usually kept in around a 1 foot cube style cage and I would imagine a carpet to be about the same.

Sharing more about the setup may help us resolve the problem.