When you're writing a business book - or indeed any business writing - WHAT you're saying is the most important thing, of course.
But HOW you say it can make all the difference as to how people read it. I asked a group of editors what really pushed their buttons, and compiled this run-down of mistakes to avoid if you want to make a good impression. This is especially important if you're submitting a book proposal, but nailing this stuff will improve your credibility with all sorts of readers.
Spoiler alert: these might not be quite what you expect...