Before you can truly get to clear communication, you need to have clear thinking. 

Neither of these “just happens” because you want it to. Generally, neither of these comes complete “right out of the box”. Our society and education system do not directly reward clear thought or effective communication. An excellent education teaches you how to think, not necessarily what to think, or what bits to repeat back when asked on a test. Learning to communicate clearly can’t take place outside an environment where you can, or need, to communicate. Being around others and learning the basics is a start, but the real learning takes place when you have to express an idea or story to someone who doesn’t have the same background or beliefs you do. This makes you shelve your assumptions. Then you have to make sure that the words and phrases you use are understood the way you use them.