You may have already heard this golden rule in sales: People don't buy from people they don't trust.

But for salespeople, it's easy to turn on autopilot and walk the buyer through the usual questions to hopefully close the deal. Too often, though, that approach doesn't work. Instead, you need to find out what each of your buyers care about, what frustrates them, and what you share in common.

One way to understand what motivates your buyer is to apply a personality model, such as the DISC model, which identifies four key types of personalities: dominant, inspiring, supportive, and cautious.

Typically, people score higher in one trait than the rest; and, after talking to someone for a few minutes, you can usually get a feel for that person's dominant trait.

Here is a summary of how each personality type thinks and some approaches you can use when selling to them.

1. Dominant

Signs you're working with a dominant person: She is confident and assertive in her speech and body language. She knows what she wants and makes declarative statements instead of asking questions.

Who they are: People who are high in dominance are motivated by control and achievement. They focus mostly on results and the bottom line. There isn't a problem they can't solve—and they love being asked. They'll accept a question as an invitation to take control over a situation.

How to sell to them: First, sell them on the idea of power and accomplishing goals. Explain how implementing your solution means they can take back control over their team's productivity, or another pain point they have yet to solve.

Then, with figures and facts, show them proof your product or service works. Demonstrate real cases where your clients have seen a dramatic improvement in the bottom line.

2. Inspiring

Signs you're working with an inspiring person: He is laid-back and happy to listen to your spiel. Afterward, he'll take interest in getting to know you by asking a question that relates to you personally.

Who they are: These people are innovators. They'll be the first to adopt a new system. They're outgoing and connect well with others. But, one key trait to use to your advantage is that they value what's different.

How to sell to them: Sell them on the distinctive aspects of your product or service. What makes it unique? Remember, they don't want to be like everyone else, and they're willing to try new processes to gain an edge on the competition and broadcast their success.

Offer referral incentives for sharing your product or service with their contacts—something they're usually happy to do. Make them feel appreciated for doing so.

3. Supportive

Signs you're working with a supportive person: She'll want to get the team or decision-maker involved right away, or wait to discuss with someone else on the team before going any further.

Who they are: Supportive people are steady and reliable. They prefer harmony, a stable environment, and they work hard to maintain relationships. They don't like to be rushed; they need time to let thoughts marinate. Though they may be slow-going, they'll take action or make a decision after thoughtful consideration.

How to sell to them: When selling to this personality type, building a strong relationship over time is key. They might not buy right away, but if you keep in touch consistently and prove you're reliable, they'll be more likely to trust you.

The next step is to convince them your solution is the right one for them. Provide testimonials and case studies from businesses to which they can relate to show the impact your solution has had on others.

4. Cautious

Signs you're working with a cautious person: He doesn't want any nonsense and asks you to get straight to the point. Then he'll ask several detailed questions.

Who they are: For cautious people, excellence is in the details. They leave no stone unturned when researching a product or service. They focus on facts and rules because they fear being wrong.

How to sell to them: When selling to this type of person, focus first on validating their thoughts, ideas, and emotions. Cautious people's intense aversion to incorrectness means they love being right; don't be afraid to applaud their correctness.

Also, provide plenty of detailed information, facts, and statistics about the success of other businesses using your solution. Prove to them they can't fail. Be thorough when describing how everything works, too. Use a visual step-by-step guide or a video to keep them engaged and help break up the text of your presentation.

* * *

Though not everyone you work with will fit perfectly into just one of these categories, you can still successfully connect with them by understanding their dominant thinking style or where their head is at that moment. Simply look at the signs right from the beginning, and don't overthink it. Meet them where they're at, and they'll be more open to what your solution can do for them.

Which personality type do you think is most challenging to sell to? Share in the comments below!