What are your favorite things to detail in your world?

I'm not sure where i got this idea from, but i love to think about the flow of money in my world. Rich people trade in gold and gems, the middle class trade in copper coins, farmers are paid in silver and poor people trade in goods. The economy is also not based on supply and demand, but on what the ruling sorcerers want people to have. For example, magic makes unlimited food so everyone has access to basic necessities, but they control luxury goods to keep the rich in check.<br><br>I often think about these details, especially when i use magic, because it can be used to solve all problems so i need to find some counter balance.<br><br>What details do you like to think about in your world or when you want to create a new element for your world?