When you’re building that alien culture, the one that will make your Sci Fi novel un-put-down-able, think about where your alien culture can meet humanity. The purpose of the alien culture should be to hold a mirror up to ourselves.
An example given on the Culture By Any Other Name panel was this…
You’re traveling in a space ship that has catastrophic engine failure. After floating aimlessly about for enough time to be desperate you encounter an alien culture. They have a replacement engine for you. They’ll happily give it, for a price. T
hey want kittens in return. More over they want the kitten’s owners to come and give the kittens as a sacrifice. What do you do? Do you make small adorable children bring their precious wiggly kittens to be devoured? Or do you say no and continue to aimlessly float praying someone else will come alone to help you before you all die?