At some point in time, every woodworker has cursed the fact that wood expands in humid weather and contracts in dry weather. Because of it, lumber that was once straight became curved, twisted, or both. Parts that once fit snugly became loose, or impossibly tight.
Turning green (freshly cut) wood was how I learned firsthand how much wood can move, and how quickly it can move. I got hooked on turning goblets, which were fun to turn, and could be turned in an afternoon. I learned a lot about grain direction, wood’s strengths and weaknesses, and, after about a week’s time drying, how much wood could change shape as it dried.
I have added three goblets to my website that are for sale, at a price of $30 each.
As long as we are dealing with solid lumber, wood movement is inevitable. Don’t ignore it and don’t fight it. Accept it.
When designing, I take wood movement into consideration. Sometimes that means using wood cut a certain way (e.g. quartersawn) to focus the expansion and contraction in one direction. Other times, it means using reinforcement (e.g. battens) to keep things aligned. And sometimes, it means just letting the wood do whatever it wants.
If you are interested in learning more about turning goblets from green wood, I recommend Turning Green Wood by Michael O’Donnell, one of the books on my page, Recommended Readings.