1.Become a pilot ? this one isn't that easy and can take years to actually achieve, but pilots get to fly the planes, not only for free, but they're paid to do so. Sadly you can't choose the destination even if you are the one behind the wheel.
2.Smuggle yourself aboard in a suitcase ? the flight may be cramped, even more so than flying economy, but the rewards are that you're flying for free. Best avoid trips to the USA in a suitcase as they may not like the intrusion.
3.Flash a badge and pretend to impound the plane ? it worked for Face Man in the A-Team, so maybe it could work for anyone. A little confidence goes a long way in grabbing free flights.
4.Probably the most practical is to save using ? there are many different loyalty programmes that allow you to save for as rewards when you do everyday activities, such as when you buy your shopping, fill up your car or even pay your electricity bill.