I will not pay for any food or drink via buy on board. It's either free or I'll go without.
I avoid eating beef steak as much as possible outside of Australia and New Zealand. The only exception that springs to mind immediately is South Africa. (Note I said beef steak, not beef in total, which I'll still eat). Main reason is because outside of Australia, New Zealand and South Africa, not a lot of people know how to cook a steak decently (most overcook, so you get a dry tasteless shred or the sole of a boot). Same thing in the air (yes, some airlines do a good filet in the air, but unless the alternative is rubbish I'll not take the chance, even though, yes, I could always send it back).
I will not drink Fosters.
Although I'm fairly open minded in the culinary sense, I'm pretty timid eating any meat outside of the standard mainstream selection. Ditto that even more for seafood.
I often only drink bottled or filtered water. No matter where I am, I very rarely drink water from the tap (and at a minimum, I will boil it).
I often insist on carrying my own bags. I rarely rely on porters or anyone offering to take a bag for me, and will often decline offers.