JMN2 wrote:I take an empty water bottle with me, if it seems the water is drinkable I fill it up in the airport toilet, if water seems dodgy I buy a bottle. Usually I buy a snack from Pret a Manger, either all day breakfast sandwich or ham and cheese (Jarlsberg) baguette. Alcohol on board makes me drowsy, I'd rather hit the pubs when I land.
I also take an empty water bottle with me. Once air-side through customs etc I fill it up from a water fountain [usually near the toilets]. And if there is no such fountain then I ask at a bar or cafe. I've never been questioned on the latter, never mind charged, IME they're happy to help.
If it's a budget airline and a longer flight I'll eat at the airport pre-departure, or have brought a sani and couple of bananas with me, as the latter are an ideal longer-duration source of energy. On budget airlines the inflight offerings are expensive and poor, but with a bit of planning you're not at the airlines mercy.
Quite often I'll also check the F+B outlets available at the airports I'm travelling through. For example here abroad I simply can't get fish and chips, or steak pie, etc so that's something I'd look our for at Heathrow etc, or good sausages [Munich*], decent curry [many ports of call in SE Asia]. If you know there's good F+B awaiting at an airport it makes the time waiting to fly fly by.
* If you've a few hours in transit, and can be bothered going in/out to streetside, last time I was there they had a beer-garden right outside with great F+B. And just 20-30M away a supermarket where we loaded up local produce we can't get here, at high-street prices, sausages, sliced meats, cheeses etc