Not sure who Trump went to for advice on this particular summit. Maybe no one. One thing Trump has been getting right is to make sure Kim is allowed to save face. This is important in these cultures. Make those you are negotiating with believe they got a good deal. Of course Trump has been doing that all his life.
Giving up these war games was low hanging fruit and made Kim feel like he won something. So was meeting Kim one on one and showing respect without resorting to Obama-style groveling. Trump struck the perfect balance. We shall see how this plays out.
Best interpretation I’ve seen so far..