Continental at Newark work very hard to present traffic on 2 taxiways to ATC to take to the holding points. Whilst riding the jumpseat on a DC10, the Captain remarked that some of the guys are superb at also getting the departure order correct. The lines of traffic at peak times can be huge.
At JFK, again on a jumpseat, leaving the International Terminal was a shambles. The Captain insisted on the tug pushing us way out to prevent anyone else getting passed us.
Once we were on the taxiway we twice had stop quickly to give way to traffic exiting other terminals apparently without clearance and joining the taxiways before checking in with ground.