Michael A. Covington, a senior research scientist, has a good presentation on How to Write More Clearly, Think More Clearly, and Learn Complex Material More Easily. He claimed that thinking, writing and learning are connected together. By improving those three aspects will able to amplify your intelligence. There are 97 slides worth of materials which are all great summaries:
Decide what you are writing and whom.
If you can’t envision the audience, try using yourself as a sample.
If someone had needed to give you this information 6 months ago, how should they have done it?