There's one nasty habit that will tell people you're missing manners.

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Brainstorming sessions are always wildly productive and creative. Get everybody together in either the conference or break room with a Subway Classic Combo Sandwich Platter, and let everybody start throwing out ideas. No holds barred. Everybody starts talking over each other and nobody notices.

I have a buddy, Jay. I've walked up to him while he was in the middle of a conversation with someone else. All he had to do was mention it once. That it's pretty rude to interrupt a conversation already in progress. I've always made a point of joining the conversation, already in progress, waiting to be acknowledged and greeted and then chime in my two cents worth.

Business Insider put together a list of things most people consider rude. Interrupting someone was the second most common rude thing we do to one another. The most common thing? Not saying "thank you". Or, writing a "thank you" note.

Note to self: be more polite and grateful.