In this tutorial that I recently published I talk about the issues you can run into and provide some examples. The examples shows how the mutable nature of objects can cause some unexpected consequences.
I then followed up this tutorial with a second tutorial that shows a possible solution. The solution is cloning objects. This is a technique commonly used in functional programming and is great to be aware of. I think the two tutorials together can be a great help.
What tutorials would you like to see?