The two things your customers and clients want most from you.
1. Make them feel important
2. Solve one of their problems
No one wants to feel like one of a number. We all want to feel special and important. Your customers will reward the people that do that for them with their time, business and referrals.
None of your customers expect or even want you to solve all of their problems but they do want you to solve at least one of them. You must be able to articulate that you can and actually execute a plan to solve one other their problems.
This instruction, though brief, if you will keep it in mind whenever talking with a customer or client will be amongst the most valuable things you have ever done.