TIP 2: Always use the simplest, clearest and most direct word available.
Your goal with business writing is to convey your meaning as directly as possible, so always use the simplest, clearest and most direct word available. Your words should be a transparent glass through which we view your ideas, not an overly elaborate painting that distracts us.
Two words that always jar with me are ‘myriad’ and ‘utilise’. Neither word adds anything to ‘many’ or ‘use’, so why not go for the simpler, shorter version?
I’m not suggesting that you should avoid all words longer than two syllables, and peppering your copy with the odd, more florid, word can add colour, but use them sparingly and they will have greater impact.