Always as said push cages and wear gloves and know how to recognise a cage which is top heavy and likely to fall over. They need loading and securing carefully, usually three in a row with one turned through a right angle but in a different column each time. Then the strap must not pull straight across the body, but be anchored one row forward each side so that it pulls the load forward, rather than uselessly pulls the sides of the body inwards. If the cages fold up and can be grouped into five or six then returned empties must be loaded across the vehicle and each row secured. If cages break free they can easily burst through a roller shutter. Be careful on the tail lift if one gets out of control let it go or it will have you off too and at night you could be on the ground a long time.
The bread companies used to sometimes load their wheeled trollies so that as the load comes off, the empties can be stacked all along one side of the body and fill up with empties from the front after a fair number of rows of loaded ones have been delivered. It sounds impossible but it works. They used load - lok poles.
If you are delivering to unattended premises at night then find out what the procedure is .Do you ring the yard on arrival and departure or what? at the very least it is charged mobile in pocket.