I have just a couple more things to touch on in regards to planning panels, and they're all very specific and very broad at the same time: Close-ups, vertical panels, and the 180° rule.
When a single subject is large on the page, that lets the reader know that something big and important is happening. This could be an important plot element, or a deeply dramatic moment.
It helps that these panels are more or less moment to moment, but the third panel close-up takes up nearly half of the page, slowing down the pace a lot. Oftentimes, a bigger panel means more time is encapsulated within, freezing a moment in time.
Close-ups don't always have to mean the action is slowed down, it can still be read as a quick sequence of events.
Obviously, you're not meant to dwell on the second panel for too long. It's meant to be a big, in-your-face moment of the superfolks arriving on the scene of a crime, before they take care of business.
Close-ups are a useful tool for amplifying certain moments, but take care to not overuse them, especially when they aren't needed... The lure of using up more of the page with less rendering effort can be strong.
Vertical panels that span the entire height of the page have a specific utility, but you need to handle them carefully in order to maximize their effectiveness. In researching this aspect of comics, I didn't find very many examples, but for a few:
In this example from Blacksad Volume 1, the 1st panel is used to set up Blacksad's destination in all it's verticality: a very tall skyscraper.
In a similar example from Watchmen, The artist Dave Gibbons has made a vast, vertical panel showing an enormous Dr. Manhattan.
On these pages, the intent was to show a large, intimidating subject-- portraying an element of power, both metaphorical and literal.
Note that with both examples, the narration sticks to the top of the page, for good reason. If dialogue trails down near the bottom of the panel, it is with more effort that the reader has to travel back to the top of the page, where the next panel is waiting to be read. This is far from the most egregious faux pas that an artist could make, but it is still in the spirit of maintaining a good flow of dialogue or narration.
With vertical panels that do not span the entire height of a page, there's a little more wiggle room to place word balloons lower, as there's less space for the reader's eyeballs to get to the next panel. I would still keep them around the upper 50%, as you can see in panel 5 of this page of the critically acclaimed erotic comic Business Casual:
Keep in mind this is a more subjective rule, as a savvy reader will logically know where they should be going next on a comic page, if you've laid out the panels in a neat and tidy way.
THE 180° RULE
This is a basic rule in comics enforcing clarity in a scene, regarding your choice of camera angles.
Imagine two people talking. If we visualize these two people as opposite points on a circle, then the circumference on either side of them forms 180°.
The idea of the 180° rule is that when you are switching camera angles as a scene progresses, it's a good idea to stay within these 180 degrees. An abrupt shift outside of this zone is jarring to a reader and can jeopardize their understanding of where everyone is and what they're interacting with.
With the example above, a reader may interpret that Angry Pancake Rabbit had swiveled completely around to point the finger at someone behind them, rather than the Defensive Rabbit that was situated to the right. In hindsight, after processing the page, a reader will likely piece together your intent, but ideally the scene would be clear at first glance, rather than after several read-throughs, trying to decipher your decisions.
It is absolutely possible to transition outside of the 180° zone, but you must take care to continue to clearly establish people's positions in a scene. Practice makes perfect, as with all aspects of comic-making.
That will wrap up this session of Making Comics With Meesh. Next time, I'll touch on effective word balloons and typography. I hope you enjoyed!