To often we assume that whatever we've attempted to communicate was received just the way we sent it and, unfortunately, more often than not that's just not the case. If you're communicating with someone (especially if it's important!), make sure that you follow up after you've communicated. Assuming that your message was heard and understand is a big no-no in the effective communication world. No matter how obvious your message might seem, it never hurts to follow up!