There’s a fine line between telling your readers too much and not enough, and your publisher won’t ask you to pick a side; he’ll tell you to tightrope the thing over Niagara Falls and back.
So how do you, you know, do this impossible task?
Well, you need to take a good hard look at the scene you're writing and ask yourself: If the vein is pulsating visibly in Jack Rager’s head…do I reallyneed to say he’s angry, too? Can’t they see that? Haven’t I shown them enough?? He just punched a mirror for goodness sake! He has shards of glass poking out of his knuckles!—Get the point?
The best way to assure that you’re not explaining too much and your readers can still understand the scene is to describe the physical details vividly. Yes, add some key commentary into the scene, don’t lose your protagonist’s viewpoint, but show, show, show!
If Rager’s pulsing veins and bloody fist aren’t enough, then nothing will satisfy the reader.
Most importantly, remember not to underestimate your reader. Our brains naturally fill in details between the lines. If you tell them Jack Rager was leaving footprints in the dust of the foyer of the abandoned house of St. Holy Lane, then they’ll already be creating the rest of the picture for you. They’ll see the dead rat in the corner, the eerie moonlight exposing a broken chair by the wall and the scratches disappearing beneath the basement door.
Read back through some of your favorite books and see how much detail they provided and compare that with what you were imagining. It’s quite different, you’ll find, and it’s the reason why when we watch the movie interpretations of these same books, we don’t always understand the director’s choice in sets. “Where’s the broken chair?” we ask. “And there shouldn’t be a hallway there; that’s where the hairless cat painting hung!”
In the end, if there’s something we should’ve said or said too much about, it’ll be someone else that catches it. After all, we knew all along that the reason why Jack hated everybody and everything to do with art was because his mother never liked the finger paintings he brought home from preschool, but sometimes we forget that the reader doesn’t also know this, too, and that’s okay.
Leave it to your trusted first reader to pick out these things. By all means, be as proactive as possible. Make checklists and charts and sticky-note reminders, but make sure you let someone else (preferably someone with a background in writing) read it before you waste your time and money on stamps and SASEs.
You can’t catch everything, but two heads are, most certainly, still better than one.
