Many years ago, to minimize airfare, I would fly from Hong Kong to whichever European city I wanted to visit. Between Hong Kong and Manila, I took advantage of Cebu Pacific's seat sales. Not sure if this strategy still works, especially with the surge in fuel prices in the last couple of years.
Now, I just book Emirates. It's among the safest airlines, and I don't need to sit in a plane for more than 10 hours per leg. Pricing of Turkish Airlines and Thai Airways are also competitive, but I steer clear of airlines that still have Boeing 737 Max in their fleet. Qatar Air is great but quite expensive. Etihad operates older aircrafts.
To save on food, just grab a sandwich or salad from a convenience store. Tap water in many European countries are potable (check beforehand) so bring your tumbler.
