Tom Black grew up in a boxcar. When he first began working, he was 17 years old and selling books for the Southwestern Company, famous for its hiring of college students to sell reference books door to door on commission. He smashed records and became a top sales manager. Now a professional sales trainer, he teaches people what he knows about selling, sales management and entrepreneurship.

Black spoke about the essentials for sales success at Entrepreneur Magazine's Growth Conference in Atlanta yesterday. Here are nine selling tips gleaned from his talk.

1. Find your own personal definition of success, then chart out the steps to your goal. There's one common denominator for success: hard work.

2. Understand the sales process. A sale happens, he says, when there's a transfer of feeling and when you bring people to a point of decision.

3. Recognize the four factors that determine results in selling:

   1. A firm foundation of values

   2. The number of people you see

   3. The quality of your presentation

   4. The quality of your prospect

4. Put faith in the law of averages -- that the outcomes of your efforts will eventually even out. In a sales culture, believing this helps support you when you have slumps or are increasing production. See more people, increase your sales, Black says.

5. Control your attitude. Happiness is a way of traveling. Most people are as happy as they make up their minds to be. If you tell yourself you feel happy and terrific, you will. Feed yourself inspirational material and use positive affirmations.

6. Embrace the belief that constant improvement is possible. And make sure your organization does as well. Get up every morning, and ask yourself, "What can I do to get better?"

7. Think big. Black says his biggest mistake has been not thinking big enough. Nobody tells you how big you can think, and you can't be afraid of it.

8. Leave your comfort zone. We all have reluctance to doing certain things, but we have to push ourselves beyond what makes us comfortable. Change is good. We all hope for something better, so remember that change isn't a bad thing. In every seeming adversity, there's a seed for growth if you look for it.

9. Commit to your goals. Goal setting is one of the most important parts of building a sales system. To set a goal, write it down, set a time frame, tell someone important to you, and set activity and results goals. Set high and low goals, and use small increments.

What do you think is essential to sales success? Do you agree with Tom's advice? 

Related: How to Follow Up Sales Leads