Here's the rule:
"Eliminate “protagonist + sense verb” phrases that make us watch your protagonist have an internal experience, and instead simply dramatize the internal experience."That doesn't come from me, that's from the (terrific!) article A Straightforward Technique to Make Your Writing More Immediate and Effective by Cheryl B. Klein over at Brooklyn Arden. (Thanks to +Elizabeth S. Craig for sharing the link.)
What I love even more than the advice is that the author gives examples that do a fine job of illustrating her point. For example:
A) Katherine heard a man shout, "LORD GIVE ME PATIENCE!" and spun to see what was happening. She saw that a clown was dancing merrily across the parking lot, a small dog in a red ruff nipping at its heels.There's two things here: a person (the protagonist) and a camera. Even if one is writing from the point of view of the protagonist (using either the first or limited third person) one should be the camera. The camera doesn't think or feel or believe or hope, all it does is record what's out there, what's happening. At least, that's how I think of it.
B) "LORD GIVE ME PATIENCE!" a man shouted behind Katherine. She spun to see what was happening. A clown was dancing merrily across the parking lot, a small dog in a red ruff nipping at its heels.
For instance, using Cheryl Klein's examples:
In (A) the reader is placed in Katherine's mind and filters everything through what Katherine hears, thinks, smells, etc.
In (B) the reader takes up the perspective of the camera. Yes, it's positioned inside Katherine's head, but it sees the world rather than Katherine's sensory impressions.
These words can be a tip off that you're talking about what a character senses rather than about the the thing(s) the character is sensing:
That list, from Cheryl's article, can be extended by adding any sense term: taste, believe, etc.
As Cheryl points out, sometimes we do want to observe our characters, we want to talk about what they see and feel and believe rather than the world in which they see and feel and believe it.
Cheryl B. Klein has written a great article on how to make one's writing clearer, I encourage you all to read it for yourself; it's short, clear and has good examples.
I'll leave you with something I picked up from reading Stephen King's On Writing, though perhaps he never says it quite like this: clarity is king. We need to make adjustments if we want to talk about the world but instead talk about how our characters see the world.
(Being hung up on one's character's inner states is very different from showing who your character is by the unique way they see the world; what they notice. For instance, a firebug might notice fire the way a designer would notice the line of a coat. But this kind of subtle characterization can be done without calling attention to a character's thoughts.)
Photo credit: "Grace and... Disgrace" by Zach Dischner under Creative Commons Attribution 2.0.