A staggering amount has been written on how to be a good salesperson. A lot of it is great, but there's an easy way to cut through the clutter. Here are seven simple activities that, in my experience, consistently separate high-performing salespeople from the rest. Whether you are selling your own product or are managing a sales team, these are the most effective things you can do to close more deals.

1. They make a good first impression.

According to scientific studies, you have very little time to make an impression when meeting someone new. About seven seconds, in fact. And if it’s not a good impression, you’ll struggle to overcome it. Top salespeople know that it's important to look sharp and speak well during those first meetings with prospects and customers, because that’s how they will be remembered.

2. They have a positive attitude.

People want to associate with others who are enthusiastic and who have an overall positive attitude. Of course, everyone has bad days, but the best salespeople don't display these feelings in front of clients. They take a day off or, better yet, develop personal techniques to manage those emotions. One very successful salesperson I knew would go home and change his suit if he was having a bad day. That process gave him a needed break and helped him shift back into positivity and high performance.

3. They take notes.

A few minutes after a meeting, most people will have already forgotten huge portions of what the other person said. So, when top salespeople hear important information--during, for instance, a meeting with a decision maker about a sale--they take notes. The clients will remember what they asked for and the promises they were made. Top salespeople remember, too.

4. They keep their commitments.

Trust is a key component in any relationship, and it is especially important in sales. When top salespeople make promises, they keep their commitments, reinforcing to clients that they can be trusted.

5. They know their stuff.

Top salespeople know everything there is to know about their products and their competitors. But, above all, they know their customers' needs. According to a survey of customer-buying attributes we conducted, the top reasons buyers selected a particular supplier was because they felt that the salesperson understood their needs best.

6. They welcome complaints.

The best salespeople don't shy away from criticism or become defensive when they encounter a complaining customer. In fact, they welcome these situations. Surveys have shown that when customers complain, it signals that they actually want to keep doing business with the company--provided the problem is addressed. (For more on how best to manage complaints, go here.)

7. They never give up.

A sales career isn’t always easy. Sometimes--like when you lose a big sale or a big customer--it can be downright depressing. But, even in the worst of times, success is often right around the corner. Rather than give up, the top-performing salespeople concentrate on all the reasons they can succeed. And they find a way to win.