Turn up 2-3 minutes before, plug into the spare socket, watch and listen. Sometimes the one vacating is too busy too explain it all (good board management helps), so only once I am fully happy to take over will I let them know and agree to take control. Then flip the switch on the comms to my headset and carry on.
Sadly occassionally some do just wonder in late, but a friendly word between colleagues usually stops that from being the norm... Afterall its swings and roundabouts.
The outgoing controller will then hover for a couple of minutes or unless i let them know I'm ok.
Then just get on with it.
