Whose point of view to use?

When it comes to writing, point of view (POV for short), basically means, through which character (and his or her thoughts and feelings) will the reader be sharing the activity of the story? Unless you're writing in the first person ("I"), or using the same character's POV for the entire book (I've done this in a novella, "Comfort and Joy," in THE CHRISTMAS VISIT -- the best novella I think I've written, actually), one of the trickiest decisions to make for any scene concerns which character's POV you're going to use.

How do I decide?

I consider who's going to have the greater emotional reaction to what's happening in that scene. Who's going to be the most upset? The most stressed? The most confused?

Because the reader is, in a sense, sharing the consciousness of the POV character, the greater the emotional response the POV character has in a scene, the greater the emotional response in the reader. And that's what it's really all about, isn't it? Evoking an emotional response in the reader.

Dramatic tension doesn't have to mean car chases or runaway horses, Snidely Whiplash villains planning dastardly acts, or emotionally fraught scenes of death and destruction. There can be great drama in a simple activity like pouring a cup of coffee, depending on how the characters react to it. That's why I try to I figure out which character's reaction will be the strongest and most deeply felt in a scene, then use his or her POV.