I like the stories that have character, location, and plot development. I really don't care for the quick "let's fuck" stories where the characters have a name simply to tell who is who and getting to the climax (pun intended). I like to know what is going on inside the character's. What are they feeling and thinkings about? If it's all just about the mechanics, what's the point of reading - go watch a video. The point of reading is to get that point of view you can't get anywhere else.
I will usually try to keep chapters down around the 4k mark. Sometimes the story demands more or less. So, I split the chapters according to what the story needs.

Working on getting my first story up. It's 12 chapters so far. The story is titled "Sara and John". It's an fantasy story between a sister and brother.
Sara has been sheltered her entire life, nothing sexual or suggestive has been allowed in the house. Every detail of Sara and John's life are controlled. Then Sara see's her first porn video on her brothers computer. John figured out a way around the safe guards. Sara now has questions about what has been kept from her. Sara wants her brother John to explain things to her.
Things start slow, but the build up is worth it to see how things progress from curiosity to the hot and steamy.