A great example of a well-edited trailer is for the upcoming movie “The Shallows”. Alex Billington of firstshowing.net made a great point that the previous trailer gave away too much, but the new one was simpler and did a much better job of “whetting the appetite” as you say. http://www.firstshowing.net/2016/watch-impressive-final-trailer-for-killer-shark-thriller-the-shallows/