Haven't found much else useful in the Journey notion, but threshold guardians can be useful. You know you need to get your character to be able to do X. So you think up someone who could let them do X. And then, in order to keep the story fun, you have to dream up the reason why that someone doesn't want to give your character X -- and a way by which they can work it around that. Or you've already stuck a character in to help your character, and you want to make the story more complicated. So the natural question -- or one of them -- is to ask how can I make this character an obstacle as well as an aid? (The other natural question is how can I make helping this character a significant event to the character who is doing the helping -- but I didn't get that from the Hero's Journey. 0:)
Was working on an outline today and had no idea what would happen when certain characters got certain news. So I dumped a few events and said that in fact they didn't get the news to these characters and that's the problem. This particular threshold guardian is having fun.