Plausible worlds:

These are notes from the life universe and everything panel in the 1980s I believe. I’ve set a goal to transfer content from my old cassette tapes of past LTUE writing symposiums to become future writing blogs. Then I need to throw the cassette tape away. Thus I accomplish three goals 1. Receive recommendations for better writing for myself and others 2. Walk in place and get a little exercising as I listen. 3. Get rid of old cassette tapes.

We’ll see how long this goal works. If I could do a couple of tapes a week I will feel very accomplished.

In science fiction fantasy you need to create a world people believe in. For example one writer has a horse traveling 75 miles a day for three weeks at a time. This is the speed of the car not a horse. A horse walks the same length the distance as a human.
We need to be willing to read all types of books, watch documentaries such as nova, and other multiple avenues of knowledge.
Have a character actions intermixed with setting and that can help build that setting.
We can use metaphors, for example: one book had a dog turning a wheel that moved the spit over fire to cook the meat.
characters give your scenes meaning.
In the book Dracula, considerable time was spent on the protagonist being driven to Dracula’s estate. The details of how the villagers characters looked at this individual as they exited the carriage started building the mood and sense of apprehension.
Scenes can reveal details interspersed with the actions the character. Dave Wolverton suggested instead of having a guy drinking a beer in a bar, for fantasy he drinks a yeasty tankard of ale.
Readers will fill in details if you have one or two good scene setting examples. You don’t have to say that it building is big. indicate there are 20 doors from one end of the hall to the other. Or you might have huge double doors in the entrance way to indicate how big the room is.
Use language appropriate for the setting.
Seek out the scenes which made an impression in your own reading and study them and see what the author did to make them memorable.
If you want to introduce a new scene have it seen through the eyes of a stranger where everything is new to them.
One author in providing a sense of the old decrepit hotel room simply indicated a stain on the carpet at the bottom of an air-conditioner. The reader is able to extrapolate the rest from that one image.
Learn what genre or readers expect from your type of book. Remember that other authors have already spent time building the troops for your type of fiction. You can tap into that previously assumed knowledge and go from there.
Paul Addison suggested putting three sensory details on each page.
Beta readers can tell you when there is too has to detail or too little.
You need to have plot and characters move the story forward.
Everything you write should serve a purpose.
If multiple readers make the same observation that identifies a trend.