I just help foster dialogue by asking questions.
"Hey, character X did this -- what do you all think about that motive?"
Or I do mini comments in the Creator's Note:
"Looks like Character Y decided this was the perfect time for clown hours"
I also show WIPS, character concepts, and just...talk about the process. It helps to talk about why the project is so important to me and also gets people excited to see more. When they see the why behind it, they can truly see "how" awesome it'll be.
Sometimes, though rarely, I comment on my updates, talking about what inspired me for this update or what I had trouble with, or how I felt when creating it. And people respond with bigger replies. For people to get excited, it helps for the creator to be excited as well.