Flashbacks
I don't know if I've ever seen better manipulation of the old flashbacks gambit. I've seen most of Sayles' movies - I would say he's known more for his writing, his storytelling, than for innovative camera work. He certainly knows how to use the camera and set up shots, but he doesn't usually draw attention to it.
But the flashback transitions in Lone Star are seamless and riveting. Past and present in one shot, no edits. Sayles has said the movie is about borders, not just just geographical but personal as well - "a border is where you draw a line and say 'This is where I end and somebody else begins.'" The way he presents this idea visually, with the camera panning from today to yesterday to today again, is stunning.
Most films present flashbacks starting with an actor in the shot narrating, then fadeout/fade-in or quick cut to the past. I can't recall seeing Sayles' technique used before.