Watch what you eat before you fly. You don't want your stomach to be completely empty, especially if you're anxious, but you don't want to eat a heavy meal, either. Avoid alcohol, caffeine, greasy or salty foods and any foods that you know to upset your stomach.
Do not look sideways or out the window once the plane starts moving. Also, don't try to read while the plane is roaring down the runway. The movement of your eyes and head will send more mixed signals to your brain, which is already grappling with conflicting information from your inner ear, eyes and the rest of your body. Try to look far ahead down the cabin and keep your gaze steady.
Do some deep-breathing exercises. Lamaze-type breathing patterns can help to alleviate nausea, whether it's caused by motion sickness or anxiety.
Yawn as if you're really sleepy, opening your mouth wide and stretching your jaw. This may equalize the pressure in your inner ear, which will help control motion sickness.
Open up the air vents and point them towards your face. Occasionally, nausea during a flight is caused or exacerbated by poor ventilation.
Try putting some ice in your mouth or chewing on pieces of ginger or taking small sips of ginger ale. These tricks sometimes quell nausea — ginger is good for digestion and settles an upset stomach — and the motion of chewing can equalize inner ear pressure.
When you feel the nausea coming on strong, do some quiet but forceful coughs — the kind you would do leading up to the point of vomiting (without vomiting, of course).
Talk to your doctor. If you have persistent problems with motion sickness, you may need a prescription medication to get relief. If your nausea is due to anxiety, and things like breathing exercises and meditation aren't working, you may need anti-anxiety drugs. In either case, herbal supplements are available that generally don't cause drowsiness or side effects — they don't work for everyone, but they may do the trick.