At New York, British Airways have a half share in their own terminal which makes for a much quieter experience on the ground.
To get to the British Airways Terraces Lounge at JFK double back up the small escalator (which also leads to the United lounge) there is a reception desk for the BA lounge at the top. First (Golds, and one world Emerald) is on the left, Business (and Silvers) are on the right.