There are a few star performers in sales. The other 99% fall on a continuum from very good to poor.

The common approach is to hold up the 1% as models for everyone else: “Strive to be a star.” But while that may motivate a few, it doesn’t help the vast majority of salespeople who want to sell more—but don’t know how to go beyond where they are.

It doesn’t have to be so complicated. Many salespeople do things that bother customers, resulting in losing sales unnecessarily. Selling is hard enough without the weight of attitudes and behaviors that make it tougher to make more sales.

Here are 20 reasons you might be falling behind in sales:

1) Trying too hard. Even if a customer may want to say yes, if they feel pushed to make a decision, they’ll say no instead as a way to escape.

2) Preparing inadequately. Avoid using canned or rote presentations that are so general they’re meaningless. Never emphasize the product or service without referencing what makes it relevant to the customer.

3) Ignoring the customer. Too many salespeople try to impress customers with “war stories” and facts. The customer wants to know how their purchase will change or improve their life, help them feel better about themselves and fulfill a dream. Customers try to figure out whether or not you’re genuinely interested in them—any answer other than “yes” means a lost sale.

4) Talking too much. Oftentimes, when salespeople don’t know what to say next, they cover it up with more talk. Instead, use these moments to ask questions.

5) Laying on the jargon. Some salespeople think it makes them seem more confident and competent if they use a “secret language” to sound like an expert. But this tactic usually makes customers feel uncomfortable.

6) Not following through. Prioritizing closing sales above all else often means ignoring emails, making mistakes, not returning calls, forgetting to send requested information and missing deadlines.

7) Writing off prospects. How many times has a prospect become a customer long after the salesperson dropped them? There’s no telling how many more sales you could make just by keeping in better touch.

8) Lacking enthusiasm. Whether it’s a clerk at a drycleaner store, a server at a restaurant, a loan officer at a bank or an insurance salesperson, it takes energy and enthusiasm to engage customers.

9) Playing a role. It’s never deliberate, but it happens: Your words, manner, and attitude can make you come across as if you’re playing a part or following a script. Be authentic.

10) Failing to involve customers. It’s not only inexperienced salespeople who are guilty of talking at customers, not with them. Don’t be determined to grab the reins and keep control at all cost—you may win the battle, but you’ll lose the war.

11) Focusing too much on what you want to sell. It’s one thing to be enthusiastic about your product or service. It’s a problem to make customers feel like you’re selling is all that matters.

12) Stopped learning. If you’re frozen in time—most likely at when you first went into sales—customers may view you as out of touch and worry you’re unable to help meet their current challenges and opportunities.

13) Believing you can sell anything. Some salespeople see this as a badge of honor and a sign of superiority, bragging freely in a self-serving attempt to put a shine on a faltering sales career.

14) Being impervious to criticism. Don’t guard their self-image at all cost—you’ll strike out at the slightest sign of criticism. Denying accusations or labeling them unfair and wrong does nothing to help you improve.

15) Not feeling valued. Everyone deserves a pat on the back, but salespeople can quantify their performance. Don’t be disturbed by a lack of appreciation—it only distracts you from getting the job done.

16) Overestimating your competence. Salespeople are prone to exaggerate their competence, their ability to work collaboratively with customers and to close sales. You can always do better.

17) Getting pumped up. No salesperson will achieve success merely by listening to motivational messages, attending seminars or buying the latest sales guru’s book. Success in sales takes focus and hard work.

18) Confusing talk with action. Because salespeople tend to be verbal, they think when they say something, they’re doing it. They readily agree to complete a proposal, make a delivery, assist with a project or make a presentation. But when the due date comes around, they’re absent—and so are their sales.

19) Talking down to customers. Some salespeople intimidate customers so they can better seize and maintain control. The few customers who don’t bail for a less patronizing experience will harbor resentment.

20) Distancing yourself from your agency. This is subtle, but customers pick up when salespeople drop hints that that they would do something differently if they were in charge. It’s an effort to earn points by showing you’re on the customer’s side, but it almost always backfires. Customers don’t want to do business with renegades.

John Graham of GrahamComm is a marketing and sales strategist-consultant and business writer. He publishes a free monthly e-bulletin, “No Nonsense Marketing & Sales.”