I've had 'seconds' volunteered to me on the last flights back from LBA & MAN (admittedly only 40 odd on the flight) and a beer with 2 brandy chasers from BRU.
Weren't being volunteered on the slightly longer flight from Faro, but they were more than happy to provide when I traipsed back to the galley.
I gather being smiley and friendly goes a long way to getting your drinks replenished