Have you ever seen how a venomous snake keeper gets the snakes attention with one hand and then comes in behind it with the other hand and grab it? Something similar to that is what I do, but with absolutely no aggression. I always grab them by their mid body and I make sure their head is facing a direction in which they will not be aggressive towards me.
I always let it be know that I'm there...i'll gently run my fingers along its spine so I don't spook it too much and then gently pick it up.