And never make your way to T5C before hand until the gate has actually been confirmed on the boards.
Definitely agree with this! The check in agent for one 777 flight to Madrid told me the stand number of B something so I stupidly took my Mum to the B lounge to enjoy more time there, only to be told at the lounge entrance that the flight was going from a bus gate in A to the stand in B so had to drag my Mum back through the tunnel - we just made it!