I have been doing serious airshow photography as an amateur for the last 5 or 6 years, and still have a long way to go to get to where I would like to be. First and foremost, I would recommend checking out Fencecheck.com, this is a website by and for aviation photographers. There are lots of tips and great examples from people posting their shots. Second, I assume you are shooting in raw, if not then you are giving up a great portion of the information in each shot, which you need for dealing with the lighting situations you will deal with at airshows. I use Av and whatever ISO I need to get a shutter speed faster than 1/2000 for jets, and use Tv with a shutter speed of 1/50 - 1/80 to get prop blur on propeller planes, and also use the Tv for any aircraft that will be low enough to get background in for blurring. At the recent airshow at NAS Oceana in Virginia Beach, VA I took over 20,000 shots over 3.5 days...and am still going through all of them! Oceana (and Langley AFB) are unique in the east coast for having night shows on the Friday of the airshow weekend; glowing afterburners, airborne fireworks displays, and often spectacular sunsets make for incredible combinations if you are lucky enough to get them all right. Just keep shooting and have fun! Here are some of my favorites so far from Oceana.