That's true, and it is important advice particularly for someone who flies often or who has to fly for their work or for other reasons. However, for occasional flyers, it may or may not be fully realistic to do that. And even so, it's sometimes useful to treat both the cause and the symptoms.

Some airlines run courses for those who have a fear of flying. Do a Google search on "fear of flying courses" etc. These can help some people. However, be careful: a lot of the people on the course will be far more scared of flying than you are, which might be comforting or it might not! But the feedback that I have heard and read from these courses has been positive.

I'm not a great flyer (though I'm OK). The advent of Walkmans, Diskmans and now iPods etc has made a big difference: if I'm nervous I choose to listen to music that I know well and that I enjoy and that is uplifting in some way.

I read: novels that are light and easy to read and that can be picked up and put down again are the best for me: I don't find that a flight is the best time to be reading heavy philosophy or a depressing tale of betrayal or whatever! Often I try to take a book that I have just started and so it is already familiar and I am fairly confident that I shall enjoy it.

if I'm on a long flight, I choose the in-flight entertainment with care: again, "feel-good" films and TV shows are better than portrayals of violence or unpleasantness if I'm feeling a bit nervous.

Whether you opt for an aisle or a window seat probably depends on your point of view. If you don't like the sense of being closed in, then an aisle seat is better. Similarly, if looking out the window merely reminds of how how you are, you're better off in an aisle or a middle seat. On the other hand, if you find that looking out the window provides a welcome distraction, then go for the window seat.

Judicious use of alcohol, if you drink, can also help you to relax. As noted above, people are quick to point out that it dehydrates you: this is not really relevant on a very short flight, and on a long flight just make sure that you drink a lot of water. Tea and, particularly, coffee can have an anti-relaxant effect, so don't overdo them. (They, too, cause dehydration.)

Finally, simple things sometimes work well. Just the acting of shutting the eyes and breathing slowly and deeply can have a relaxant effect. There are lots of more sophisticated techniques too, of course, but that works well for me: and not just when I'm flying...