If you mount a sighting device on your camera it's easier to track a moving object and you'll lessen the risk of losing it at high zoom.

Shooting fast airplanes? Try to get the sun behind you and locate yourself next to a public address speaker for running commentary and set your record level; pray for a cloudy day add a neutral density filter and don't frame in too close, you'll just lose 'em.

Stay back enough to be able to track 'em smoothly and yet see what plane it is. Even get back far enough to see the crowds turning heads every now and then.

I use a Mighty Wondercam shoulder mount and it works very well, forget using a tripod, too clumsy.

Every now and then let the plane fly outa the frame to be able to cut to a later sequence. Conversly let the plane fly into the frame occasionally.

Make sure the audio is top notch, under record if you have to, get bad distortion, it's all over.
HTH.