Less is More
Best-selling author Jerry Jenkins is well known for writing RUE in the margins of his students’ papers: resist the urge to explain. Don’t tell us what the character is feeling. Show us how she’s acting. We will relate to that and attach the corresponding emotion. Now you’ve drawn us in and are letting us actively, emotionally participate in the story.
When I judge contests, I see so many writers trying to explain a character's emotions, going on for several sentences to make sure that I’m understanding what the character is feeling. But that it just waters it down. Several well-placed words are much better than sentences. You want to pick just enough words, details, descriptions, scents, etc. to evoke the emotion in the reader.
Think about that evocative picture of John F. Kennedy, Jr. saluting his dad’s coffin. You don’t need to say anything more than that to feel a tidal wave of emotion. You don’t even really need to see the photo. In fact, if you tried to explain it, you’d water it down and create less of an emotional punch.
Leave it to their imagination
Stephen King said in On Writing that when he wrote Carrie he didn't describe the main cheerleader because everyone would picture "that girl" from their school days. Their cheerleader and all the corresponding emotions they had about cheerleaders and high school. That’s a much more effective way of reaching readers' emotions than telling them what to feel.
I dislike when I've pictured something in my mind and the author is describing it differently. For example, the layout of the house. If I think the kitchen in on the right and now she telling me it’s on the left, I can’t picture it. I can't come around to her way of thinking, and it's a disconnect. It's also why I'm not a big fan of faces on book covers. It's never how I imagine the characters.
Use details for maximum impact
Give your characters objects infused with meaning, like a locket or a pocket watch. It could even be bigger like a guitar or a classic car. We as readers know that particular object has great meaning. So when the hero takes off in the ‘66 Mustang he restored with his dad, we know he’s doing more than just taking a drive. Being in the car makes him feel close to his dad, so maybe he’s looking for wisdom or peace. As a writer, you don’t have to lay all that out. As readers, we know how we’d feel in that situation, and pulling on our own emotions will create a deeper connection than just telling us what to feel.
You want just enough pertinent detail to pull on those emotions. Glasses can be important if the character pushes them up when he's nervous. Then you don't have to say he's nervous, you can just show him pushing up glasses. Or twirling her hair. Or fiddling with her necklace. When the reader makes that connection, they're feeling that emotion. And when a reader makes an emotional connection with your characters, the won’t want to put your book down.