Don't use jargon. I know you've heard this rule before, but maybe no one has ever told you the real reason for the rule. Your choice of jargon reveals your weakness.
A lot of jargon is specific to an industry and if you use it outside the industry no one will understand you. This jargon will undermine you because you are so likely to alienate someone by using words or phrases they don't know.
There's also jargon that goes across most industries. The phrases you hear whether you're an accountant in consumer products or a programmer in health care. Most people understand this jargon, but using it makes you look bad because most cross-industry jargon is a euphemism for being desperate or incompetent or calling someone else desperate or incompetent. Here are some examples:
1.) "Let’s think out of the box" really means, "Can you creatively anemic people please come up with something?" People who really do think out of the box do it whether they are told to or not. That's how they think. If you feel like you need to tell someone to think out of the box, then it’s probably hopeless. The person who says, “Let’s think out of the box" is usually desperate for a new idea and surrounded by people who are not known for generating ideas. So the phrase is actually an announcement that says, “I’m in trouble."
2.) "I need someone who can hit the ground running" really means, "I am screwed." Because no one can hit the ground running. You need to at least assess what race you're in and who else is running. Everyone has a race strategy when they are in the blocks. You need a little time to get one. In the case of a new hire this means taking some time to assess company politics. If your employer needs you to hit the ground running then you've already missed your window to achieve success.
3.) "Do you have the bandwidth?" means "Can you really handle this?" Note that bandwidth is not time. It is something else. If you ask someone "Do you have time?" you mean, "Am I a priority?" If you ask someone "Do you have bandwidth" you mean, "You seem like your brain is fried. Can you pull yourself together to do this for me?"
4.) "Let's hit a home run" really means "I'm desperate to look good." And "Even though the odds of a home run are slim, I'm banking on one because it's the only thing that'll save me." Something for all your sports fans to remember: If you have a bunch of solid hitters you don't need a bunch of home runs.
5.) "You and I are not on the same page" really means "Get on my page. Your page is misguided." No one ever says, "We're not on the same page, so let me work really hard to understand your point of view. If you want to understand someone else, you say, "Can you tell me more about how you're thinking."