I feed some animals in the enclosure, and others out. I take my tegus out because the male is really old and the female would just rob the food out of his mouth.
I feed my yellow anaconda out because I like the interaction, and she knows when there's no more food coming.
I feed my ornate monitor in because I'm still in the taming process and he DOES NOT like being picked up yet.
Either method can work, it's up to the individual keeper and being able to read one's animals.
Chris