Pacing plays an important role in creating a salable romance novel, but it's probably one of the least understood elements of the craft of writing. Basically, pacing is the author's way of controlling how fast — or slow — a reader reads the book. The author does this by controlling the length of the sentences and paragraphs, the ratio of dialogue to narrative, and the amount of descriptive details offered in a particular scene.
Think of a scene as a song. Just as each song has its own rhythm and tempo, some fast, some slow, so will your scenes. Your choice of words, how short or long you make the sentences and paragraphs, the ratio of dialogue to narrative in your scene — all of these combine to form the pacing or tempo.
For a romance novel to succeed, it will need scenes that take away the reader's breath (fast pacing) and scenes that make the reader sigh with pleasure (slower pacing). Like most aspects of writing, finding the right balance is critical.
Generally, when you want to speed up pacing, you will use the following techniques:
Crisper, sharper nouns and verbs
Conversely, the following techniques result in a slowing pacing:
More descriptive passages
So, how do you strike the right balance? The answer largely depends upon the type of subgenre you're writing. After all, a lushly sensuous historical romance will usually have a much slower pace than a tightly plotted contemporary romantic suspense. Still, even within the same subgenres, certain scenes and situations call for a specific type of pacing.
When you're looking for ways to quicken your writing's pace, focus on making your scenes all take place in the here-and-now, rather than using flashbacks or dreams. Both techniques, as a whole, have been overdone. Even when they're used properly, they slow down the action and the story's pacing.
Another way to balance your pacing is to vary the sentence structure you use. Instead of writing sentence after sentence that follows the same “subject-verb-object” format, mix it up by trying “predicate-subject” or other variation. This, combined with varying the length of your sentences and types of scenes, should ensure your pacing is well balanced.