Jet lag disrupts your body clock by forcing you into a new time zone. But with preparation, you can sleep more easily on long flights.
Avoid caffeine before flying, and use an eye mask to block light. A neck pillow and noise-cancelling headphones help signal rest to your brain.
Try to sleep based on the time at your destination—not the time at departure—to ease the transition.
Melatonin supplements can be effective if taken in alignment with local evening at your arrival city.