To make every effort not to let the beings hurt during the process is one way. Take fish as an example. Fish might get hurt when they jump out from the containers and land either on top of the containers or on the ground. To roughly grab and quickly throw it into the water, as normally done by some, may cause harm too. Other than birds perhaps, throwing usually gives animals a great sense of fear, which in turn can be detrimental to their mental condition. 

- Quote from The Right View, "Liberating Living Beings"