Fake apologies

They turn statements into questions: a raise of pitch at the end of the sentence or an actual phrase, like "........., you know?" or "............, eh?" They indicate that you're not confident in your communication skills.

Ask a specific question instead,  such as "Does that make sense so far?"

Using big, impressive sounding words rather than smaller, common ones can leave listeners with the impression that you're pompous and pretentious.

The fix, in this case, is a big dose of humility. 

These are words or sounds you insert into sentences when you're pausing to think. Examples: 'um', 'like'. Too much of these will annoy your audience.

When you simply pause in silence, rather than trying to fill the thinking space with the hiccup, you end up sounding wise and like you're choosing your words carefully.

This consists of blurting out a stream of facts or observations before finding out which ones (if any) might actually be of interest to the listener.

To avoid this, ask questions, respond to comments, figure out what's needed, and only then trot out facts and observations that are immediately relevant.

Unoriginal expressions used so frequently that they've actually lost meaning like  "out-of-the-box thinking" could reveal a lack of respect for the listener.

Avoid metaphors completely or use original ones. If that's too hard, tweak the wording of clichés to make them less cliché-ish.

These are attempts to disguise ugly facts as abstractions. Examples: using "development opportunity" when you mean "drudgery," or saying "rightsizing" when you mean "firing people." They mark you as a coward.

You'll get more respect and credibility in the long run for telling unpleasant truths than for pleasant-sounding lies.

When you constantly take over normal words and use them in odd ways to make them sound "businessy", people will most likely roll their eyes.

Stick to using words as they're defined in the dictionary.