Ok, here's a few of my rules when it comes to panning a fast moving object:
1. Shutter speed affects the effect of motion. Slower speeds will induce more "blur" to the background, faster speeds will make the background more static. Slower speed will be more difficult to shoot as you'll need to be "on track" for longer.
2. Panning is basically moving your camera to follow the trajectory of the object. Basic guide is to move only your waist. Legs stay in place, camera and upper body as well. Start with your body half-twisted toward the object and turn to half-twisted in the other direction by the time you end.
3. Follow-through. After you fire your shot, do not immediately move your camera away. Follow through the shot for a bit more, keeping the object on track. This helps reduce the likelihood of a shot gone bad because it wasn't done processing.
4. Aperture. Because you're going to be reducing the shutter speed to induce motion, you can either adjust compensation by either lowering ISO closer to 100, tightening your aperture, or both. Personally, I'd do both and have aperture closer to between 7.1 to 11.0. In panning, the background will be blurred anyway, so bokeh is not a factor and it increases the overall sharpness of the object. May vary if lighting conditions are not ideal.
5. Panning is easiest when the plane is going from left to right (or right to left). This is because the distance between you and the object will not change too much, allowing the camera to easier maintain focus. This direction also produces the best "motion blur".
6. A near object will be easier to focus but will be crossing your shooting area faster. A far object will be harder to focus but will be crossing your shooting area slower. The latter gives you more time to react and take the shot but at the expense of higher chance of focusing issues. The former increases your focusing success but less reaction time to take the shot.
7. GOLDEN RULE - know your activity. You must know what you are shooting in order to do it well. How the plane flys, where it will be flying, speed it will be flying, altitude or change of altitude through the flight path etc. You need to anticipate the shot.
Other than that, it's all practice practice practice. Cars, birds, planes, bicycles, people, football, whatever.
Good luck!