A key to a good sexy story is to have a story line. You can go as simple or as complex as you like, but it needs to follow some type of theme.
Before you begin, think about what type of tale you want to convey. Is it a smutty, hard sex fantasy story? If so, a good story line could be an encounter at the bar then home for a one-night stand. If it is a medium-length story, begin at the point where your main characters are at home getting ready. Write about how the woman is shaving her pubic hair, masturbating, primping herself to be sexy like an escort. The man is talking with his buddies about they type of girl he wants, describing her body parts. If it a short story, you could fast forward to the meeting at the bar. Details areimportant too but I'll leave detail tips to the next post.
After they leave the bar, pick a location, if you are emphasizing kinky play, make it behind a bush in the dark. If you are going for romance pick a hotel room with a jacuzzi tub. You can even get extra kinky and select the bachelor pad and make the man's friend there so they can tag team...
You see where I am going with this? You can trail off wherever you want but I would suggest making a plan before you begin, this way your story has direction and your erotic stimulation is really created well. The less of the scenery change you have to describe, the better your story will be because you can focus on small detail. Unless you are writing a novel, I would advice never going beyond 2 different focal points of place in your erotic story because you will confuse your readers and will stray from the sexy moon in your sexy story that you are writing.
Write a sexy story with few locations to promote more erotic mood. The erotic story writing technique always focuses on the sense of touch and sight. Sometimes smell but this is usually an advanced erotic author's mention because it's all about creating and encapsulating a mood that the reader really feels a part of, they are as aroused sexually as the characters in the story. Write down your plan with your scene and then fit everything into the place you have chosen.