In all honesty, I'm not sure there's actually a way to TEACH the writing of decent chapter endings. It's something that the sensitive writer will develop over time, as a result of LOTS of reading and LOTS of writing practice.
The most helpful thing, I think, is to give you a few rules of thumb.
1. Each chapter ending should propel the reader forward. That DOES NOT mean that every chapter ending is a cliff-hanger. If you do that, you'll end up sounding like a Hardy Boys knock-off (have you ever read Hardy Boys books? Ugh!). The trick to a chapter ending is CONFLICT, the same way CONFLICT plays such a vital role in the OPENING of a novel and THROUGHOUT the novel. It's CONFLICT that will propel the reader to the next chapter. And that may or may not be a typical cliff-hanger.
2. Chapter endings should not all follow the same formula. Of course you're going to want some cliff-hangers thrown in there, but if you do that at the end of every chapter, your readers are going to start to roll their collective eyes. The key is variety--a careful balance of endings that keeps the story moving forward.
3. Quiet chapter endings can be as compelling as tense ones. In fact, sometimes the quiet chapter ending hints at more terrible things to come by presenting a false sense of calm. So don't shy away from quiet endings just because you think every ending has to have a huge BANG. It doesn't.
In the end, it's all about balance. Pay attention to the overall rhythm of your story, and craft your chapter endings accordingly. And be sure to KEEP READING WELL WRITTEN BOOKS. I can't stress enough how much we learn simply by reading the work of others. GOOD work, that is. Be discerning.
Honestly? I spend a lot of time on my chapter endings. A LOT. I craft them very carefully, whether they're heartstopping or calm. I won't move on to the next chapter, in fact, until I'm completely satisfied with the ending of the chapter before.
To me, it's just that important.
Now take a look at your chapter endings. Do they carry CONFLICT toward the next chapter? Are they well balanced, so that they're not cookie cutters of each other? Or do they sound more like my all-time Favorite Dorky Schlocky Badly Written Hardy Boys chapter ending of all time:
A blunt object connected with the back of his head. Joe pitched forward and blacked out.
Oh, yeah. Good stuff there.