1. The SX10 has about as smart (if not better) than my old 300D.
Unlike the 300D, the SX10 has the Servo focusing mode. Activated from the Menu button.
2. When focus is locked and tracking, there will be a blue square. Alternatively, I used the old focus mode (green square). Keep tracking the subject until I am ready to shoot, 1/2 press and then full press the button.
3. I avoid the continuous shot mode, as I will lose track of the subject in the viewfinder. A 20X, it is nearly impossible to shot with both eyes open (i.e. one on the viewfinder and another to track the subject).
4. Make lots of shots, to ensure that nothing goes wrong.
6. To pick your subject from the wide open skies, I will open both eyes, with zoom set at widest angle. Then zoom into the subject. If I can't find it, it will move around to hunt for it. The planes move around the frame faster than you think, and unlike a grandprix, it can any anywhere in the sky.
Be careful of the sun too. It can burn your eyes and sensor, so a pair of sunglasses is not a bad idea.
Here is my past shot with the 300D and the 100-400mm L IS. Taken at max zoom, which is almost the same as our SX10's zoom @ 18X.
but to be fair, the A380 is slow moving, like a whale doing ballet ontop of waters. if it falls , I am sure of a tsunami. The weather was overcast with light rain.