Best motto is (from the perspective of a non-US citizen):

run run run

as soon as you get off the plane. I was on this flight a few weeks ago and although we arrived early we had to wait till 6 to get off the plane because immigration only opens then. Several other flights seem to get in at that time...

It only took me about 10 minutes to clear immigration but it might have been much longer if I hadn't been sitting right at the front of coach and had not run as soon as I stepped off the plane.