I have had two upgrades when flying in the back. One BA out of Delhi circa 2004, one on TWA St Louis to Little Rock after inbound flights had been delayed in JFK meaning a missed connection. As others have said, find the money and pay for ticket. I am lucky to have been upgraded from Business to First on a number of occasions with my companies favoured carriers LH, SQ, EK, but this is easier to accomplish than the initial upgrade.
As for Jet Lag get the best seat you can afford and on arrival try and stay awake until back on local time.
Cheer
Mr Mac
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