honestly, I have never practiced building methods from tutorials on minecraft ever, apart from a little organics a long time ago.
Think about your picture of what you want to build in your head as it would be in real life.
Take into account utility, what do people use these rooms for, what would people walking around this town find useful or what would be the path people would use to get from one place to another.
In nature use randomness or what would happen in nature for details (ie meanders, banks and falls on rivers and randomness for wild fields and flowers).
In civilization use utility/patterns and also be free to use what you find looks good because people do it all the time in real life. Think about wear and tear, what places would feature what (ie churches and shops in population centers, maybe gardens, nature reserves and sparser and sparser houses further out from population centers).
In terms of detail, im not really sure where to go but knowing absence of detail can be really useful when used in contrast to alot of detail.
I hope this helps, although i feel like im sort of just rambling but yeah.