As noted last week, cliffhanger chapter endings drive the story forward. But they can also inspire new dramatic events. If you have to find a way to add a scary or exciting twist at the end of the chapter, the scene automatically becomes more dramatic.
In the Haunted series, I try to keep my chapters to about 1500 words. If I can't find a cliffhanger moment within 1600 words, maybe there isn't as much action as I want. If a chapter goes longer, I split it in two—which forces me to add a new cliffhanger halfway through the chapter.
For example, in Haunted book 4: The Ghost Miner's Treasure (not yet published), I had a chapter that was going on too long. I looked back through it, especially at the 1200 to 1600 word point, to see if I had a moment I could turn into a strong chapter ending. I found this:
There was another guy in the room. He had shaggy dark hair and skin that looked like he spent every day in the sun. He stared at us a moment, with black eyes that kind of gave me a shiver, then looked down at the map spread across his table.
The old guy bustled around, pulling out books and boxes and stacking them on an empty table. I sighed. This looked like it might take awhile. Tania sat down, and I moved up next to her. I jumped back when my elbow seem to hit a wall of cold. I must've gotten too close to the ghost. There really wasn't room for all of us.
"Hey, why don't I go find Mom, while you get started," I said. "She'll worry if she doesn't know where we are."
There's something potentially dramatic there -- a physical encounter with the ghost. But they've already gotten to know the ghost, and it's just a slight brush of the elbow, so it passes in a moment. To build that into a cliffhanger chapter ending, I changed it to this:
When I glanced up, I saw the dark-haired guy staring at us, with black eyes that kind of gave me a shiver. For some reason, he reminded me of the fortune teller, and her words "Bad luck" seemed to echo in my brain.
I guess I took a step back without realizing it. I let out a yelp as I stepped into a wall of cold.
I took a small moment and made it bigger. Because the reader already knows the freezing effects of ghosts, they'll wonder what happened when Jon backed into one. This also allowed me some humor at the start of the next chapter, as Jon knocks into the museum curator. Books go flying, Jon has to somehow explain what happened, and he draws even more attention from the spooky guy.
Tip: To keep the plot action-packed, check your pacing by noting your chapter lengths. If some chapters go on much longer than others (proper length varies by genre and age range), look for places to add action.