Hi
Well I must admit I have had a good bit of luck when arriving early and getting on the early flight.
I basically ask very nicely if there is a chance I can go on the standby list for the early flight and that I have had luggage only and dont mind what seat they give me.
I dont demand or the Do You Know Who I Am, by flashing my BA Card, they know that your are silver or gold.
I have seen to many folk walk up and demand things, they basically dont do themselves any good, just be laid back and if they cant help you just say thanks anyway, it was worth a try and just be really really nice.
The thing is if you dont ask you dont get.
regards