The 2 most important things to consider

Audience and message. No matter what we write, we must always keep in mind these two elements. They are the straw that stirs the drink.
Audience - Who will be reading what we write? Have we written it in such a way that they will understand it? If we are writing about a new medical technique, and our audience is health care professionals. we don't need to explain every medical term we use. If our audience is more general, we probably do need to explain.
Message - What are we trying to get across? We should know that before we begin writing. It doesn't have to be prophetic, but we don't want it to be pathetic - and that's what the result can be if our writing has no message or purpose.
Sometimes "message" is hard to define, but here's a clue. If we read something a week ago and are telling a friend about it, whatever we are telling our friend is most likely the message we got out of it. Messages can be as subtle as the feeling we are left with after reading something. They don't have to be hammered home. In fact, sometimes they are hugs rather than hammers.