Really, I'm going somewhere with this.
On both of our flights back...no wi-fi. So, I finished 3 (short) books instead!
One of these books was Rivet Your Readers with Deep Point of View by Jill Elizabeth Nelson. I downloaded it for Kindle when it was briefly free. (And interestingly, read it after finishing George MacDonald's The Light Princess, written in the 1800s, and probably the opposite of deep POV.)
The basic idea of this book is to write "closer" to your point-of-view character. As it says very early on (you can see it in the "Look Inside" option on Amazon):
In order to remain firmly inside the (point-of-view character's) head, nothing in a scene can be presented for reader consideration that is outside that character's awareness.
Easier said than done, of course, but this brief book does a good job of defining and offers some techniques that will benefit all fiction writers. There are brief exercises, as well. (Admittedly, I was on an airplane so just typed my answers into my Kindle, instead of writing them out with detail, which may have been more useful.)
Nelson mentions basic things that I learned from other writing groups (you almost never need to use phrases like "he saw", because anything that's presented through a point-of-view character is something the character saw). She also has a lot of things I hadn't thought of. There is a very good explanation of writing your paragraphs in a linear/logical order, which will benefit all writers (even non-fiction).
For me, the main shortcoming is that (if I recall correctly) all the examples are from Nelson's own works. Obviously getting copyright clearance from other authors would have been more difficult, but I would have liked to see how other authors approach the same problems. (And I felt just a tiny bit like I was reading a sales pitch for the books cited!)
Something else this book taught me is that, as a reader, I don't actually want to read deep POV for the majority of the book. Taken out of the context of a book, I actually preferred a few of the "wrong way" examples to the "right way" examples, such as:
Shallow: Joy rocketed through Adrienne.I see where the second example is "deeper" but it didn't engage me or make me feel like I was in Adrienne's head. I never think of a grin stretching my lips. Maybe I'd feel differently reading it in the context of a book (if she'd EARNED this happiness and I could feel it with her). But standing alone, I'd rather know what happens next then read two sentences describing how she's happy.
Deep: A grin the size of the big, blue sky stretched Adrienne's lips. If her feet met the sidewalk, they sure didn't know it.
For every example I disagreed with, there were probably two where the "deep" version was stronger. Here is a gem, where I thought the Shallow was all right, but the Deep is much better:
Shallow: Despair tugged at Jenny's heart. No one ever believed her.
Deep: Jenny wilted into her chair. What was the point of trying to defend herself?
So although I discovered I actually prefer a touch of narrative distance, I'll definitely try to put some of the tips in here to use.
If you actually WANT to write deep point of view (which is a very popular style nowadays) this should help you quite a lot. Even if you don't, it's worth a read just to get clarification as to what people mean when they say "deep point of view" and to find a few tips that will tighten your writing.