Still, you should be at least thinking about page design when you're writing, even if you don't describe your perception of the page in your script. You're writing for a visual medium, and you should be thinking visually. Taking a step back, now. We've been looking at the set-up and layout of an individual page, and now we can move out and look at the page as a unit in a larger work. In any good story, you have suspense.
Tension builds in some way.
So, a good way to take advantage of the page breaks in a comic is to leave the reader in suspense at the end of a page. It can be as little as an insult thrown out in a conversation, or as much as a villain holding a knife to the throat of our hero. I'm sure that you can come up with plenty of examples of this sort of thing, so there's no need for me to quote from one of my scripts. Another use for the page break is as a natural way to introduce a new scene. End the page, end the scene.