The cards are generally stacked against someone trying to make a sale. Budget limitations, timing issues, red tape, and other factors you can't control can all come between you and a viable business deal.

But there are also subtle things we do that can negatively affect how potential clients perceive our companies. We can't always be perfect, but we can practice self-awareness to prevent costly conversation mistakes. Avoid these 10 turnoffs next time you're talking to a potential lead:

1. Name-Dropping

If you mention you're best friends with Mark Cuban within the first two minutes of a conversation, you might as well be saying, "I'm trying to impress you right now so you think I'm important." I don't think Mark's best friends are advertising it. Naturally bringing up names that fit into a conversation is OK, but don't force it.

2. Overpromising and Under-Delivering

I would love to tell someone they're going to be the next Seth Godin or Richard Branson after they work with us. But people would see right through it and think my company is making false promises. I've learned that it's better to be real with people about expectations. You have to realign them sometimes, but you'll earn a long-term client who trusts you in the end.

3. Talking About Yourself Too Much

Keeping an open ear when talking business will impress leads more than anything else. Try to go by a 60/40 rule. Spend 60 percent of the conversation listening and 40 percent talking. In sales, this number should go up to 70/30 or more.

4. Not Appearing Credible

Imagine a child wearing a business suit for this one. Just because he's dressed like a professional doesn't mean he'll do a good job. (He'll probably eat a whole bag of Cheetos and watch Scooby Doo instead.) Don't be passive about your online presence. We recently wrote a blog post about how one leader's influence affects the whole organization, which talks about how you need to take a hard look at yourself and your company. Do you have content out there that draws people back to your company in a smart way? Ask yourself whether you'd do business with your own company after doing a bit of research.

5. Lying

People you want to do business with can typically sense BS from a mile away, so don't think you're getting away with it. Ego, pride, and insecurity will shine through like headlights when you're talking to someone. Even telling innocent white lies can catch up to you sooner or later.

6. Not Valuing People's Time

Doing business with someone is a lot like dating. If someone shows up late or reschedules a first date, it should be a major red flag. Chances are that person won't value your time as a significant other. Someone's first impression of you should never be "this person doesn't value my time." Own up and apologize if you're late--don't brush it off.

7. Emphasizing Sales

Trying to sell in a social setting will deter people from working with you later on. Ninety percent of consumers say that when they're ready to buy, they'll come to you. Not every person wants what you're selling, or the timing might not be right. Know when to build a relationship and when to sell.

8. Behaving Inappropriately

It's natural to want to skip past the formalities and interact with people in a more relaxed way. But that doesn't mean you should do keg stands and make off-color jokes the first time you meet someone. Informality before rapport can be a major turnoff to many people. Wait until you know you've secured trust before you bring out the tequila shots. It's not worth the risk.

9. Acting Like a Know-It-All

If you don't have a quality answer, it's OK to say, "I don't know." This honesty draws attention to the things you do know. And by asking more questions, you can actually learn about a person and discover ways you can add value.

10. Using Poor Grammar

Emails aren't texts, and potential clients aren't your BFFs. Not every email has to be perfect, but "u" and "btw" can get on people's nerves and cause immediate judgment that's hard to shake. Slapping an "excuse the typos" onto the end won't stop people from judging you for sounding like a teenager, either.

We've all committed a few of these slipups at some point. And all it takes is ruining that first impression to jeopardize a sale forever. We're not going to land every business opportunity that comes our way, but avoiding these conversation don'ts whenever possible will increase your chances of impressing a client and landing a career-defining sale or relationship.

John Hall is the CEO of Influence & Co., a company that helps brands build their influence.