Flight Planning Websites
When using these websites, don’t use just one website for all your searches. Each of them has their own weak points, so it pays to look around. If you’re flying within Europe, it may be cheaper to fly out with one airline and back with another, but remember to check the Fare Rules for each ticket before booking.
Finally, if you’re planning a long way ahead, subscribe to the email newsletters of carriers that fly from your nearest airports to be first to hear about new routes, offers and seat sales.