Whether a novice author or a veteran of the keyboard, the author is always in danger of falling prey to the many pitfalls of writing – especially when working on sex scenes. This may be partly because genres like erotica that employ such scenes are occasionally not taken seriously by the “literati” and therefore may be taken lightly (if completely unconsciously so) by the author herself. In addition, the world is full of poorly written sex scenes, which may negatively influence the author's own art.
However, by being aware of the main pitfalls of creating a sex scene, the author is better equipped to avoid them in her own writing.
Vagueness
Vagueness can be caused by the author's own bashfulness, and can result in something that isn't a sex scene at all, but simply such a dim suggestion that the act may have occurred, that the reader is left wondering whether it actually happened at all. While this was common in much fiction of the past, today's audiences are more sophisticated. Many people have discovered that sex is a good thing, and wish to enjoy it as part of their reading experience.
Too Much Information
The other extreme, of course, is an author who is so enthusiastic about writing sex scenes, that she doesn't want to leave anything out, and ends up including too much information, such as the color of the hero's nose-hairs. An author writing such a scene will be so focused on what the characters are doing, that she will forget to express what they are experiencing. The end result tends to read much like a manual on how to put together a washing machine.
Furthering the Story
Even after the author has discovered how to craft a proper sex scene, she is still left with the challenge of how to use it to further the story. It is likely that this most often happens in erotica, if only because the erotica author has a sex quota to fill. Sex is not simply garnish that remains untouched on the reader's plate. The erotica author must remember that a sex scene is a hotbed of character interaction and should be treated as such. Using each scene to move the story forward is essential if the author wishes to actually write a good story.
There are other dangers inherent in attempting to write a first-class sex scene designed to make readers come back for more, but these three are the most basic. The bad news is, of course, that it is quite difficult to learn to write a top-notch sex scene. The good news is that the cure is practice, practice, practice.