Pacing

Plotting is an outline of the action points in your story.  Pacing is the speed at which you arrive from point to point.  Great plots are undeniably important, but drive your reader too quickly or drag out an event too much and they’ll ditch your masterpiece at the book-swap at Starbucks without a backward glance.
 
Chances are that because you’re a writer, you’re also a big reader and somewhere in all those years of reading you’ve learned a lot about writing, plotting and pacing without even knowing it. 
 
After you’ve celebrated finishing your first draft, let your writer brain have a rest and let your “reader” side step in.  I find it’s helpful to read the second draft in a form other than it was written.  It gets my brain out of the writer groove and makes the work feel fresh again. 
 
Once you have your pencil in hand, mark where the “reader” side of your brain craves more information and cross through the meandering descriptions that are heavy with the –ly’s.  Your reader brain should scream loud at anything that causes it to drift from the story.
 
As you do this, you’ll see a new shape emerging from your story.  It’s like working a clay sculpture, adding flesh to shape hips and lips, then paring off the excess around the eyes to reveal high cheek bones.  Your characters will become real, breathing human beings with secrets and motives that they may hide or reveal as needed to keep themselves moving from page to page.
 
The “reader” part of you knows if the story is moving at the right speed and only with several read-throughs will you know where to add and subtract to maintain tension and keep your audience engaged.

Trust your instincts and remember that it’s fun to leave your reader hanging at the end of a chapter.  Curiosity will keep them turning the pages.
 
One last tip: As you read through your novel/story each time, pick a different character and make sure their every action and word spoken is in line with their interior motive which may or may not be apparent to the other characters yet or even the reader.  It will tighten the plot and tension and make the reader go “Ah-ha!” at the end.