When new or potential clients ask me how we can make our first meeting as productive as possible it is an easy answer. Prepare. That means me too. I ask them to look through all of the documents, emails and information they have that is relevant to their issues. And I ask them to send me the operative contract, documents, emails and or an outline of the pertinent facts prior to the meeting.
This applies to you too. You cannot prepare too much. Knowledge is power.
If you are meeting with a salesperson, know what you need and have a plan. This helps you order what you need, not make emotional decisions and keep the meeting on point.
If you are the salesman, know the company or person you are trying to sell. Research. It helps to keep notes about people, their companies, their families, etc. The personal touch is everything (but you need to be sincere and care, or you will hurt your cause). Search the Internet, review your notes, or take whatever actions will help you be prepared for your meetings. Knowledge and preparation make meetings go smoother, and better, and more productive.
By doing so you will help yourself, and help others. Time is money is true. Most people would like more money, and we all can use more time, so prepare as well as you can and you will have a better opportunities for more of both.