I attended a Michael Hauge screenwriter's workshop, which also applied to novel writing. He said one thing that struck me as very useful. There are 4 types of characters to have in a novel or movie:
4. romantic interest
I didn't glean a ton of nifty stuff from 1, 2, or 4 (a few salient points), but my Ah Ha moment came with the Reflection. This is the sidekick, the buddy. This is the person who points out to the hero how he/she can achieve their happiness. He's the one who shows the hero a glimmer of what the future MIGHT be.
I've always had 'sidekicks' but I never thought of them in this sense before. Because of that "ah Ha" moment, I've redefined a minor character in my current WIP and I think the book is stronger because of it.
I was so energized when I came out of that workshop -- the best way to feel for a day-long event, right? I took pages of notes and now look forward to putting them all to use.
Off to write!