<strike>A good rule to follow I have found<strike>
<strike>A motto I live by</strike>
this.
Whilst the sentiment is nice, I have to say that it's something to be careful with. V4 of that post was 'Fewer words create a more powerful message.' But that's only made powerful in relation to seeing all longer edits he typed before it. If it had just been V4 in the post then it would've seemed a bit vapid. They say that 'knowledge without application is meaningless', but so is knowledge without understanding. Getting a message across in a succinct manner is important, but not at the expense of essential information.
The most powerful sentences leverage what you already know to introduce a new concept. Read anything by CS Lewis. He had this way of condensing complex ideas into the simplest sentences with no loss of meaning or nuances. I agree with rezzeJ though that less isn't more on principle.