When you seek someone’s advice and choose to follow it, let them know what happened as a result.
When someone helps you with some part of a project, let them know how it turned out.
When someone introduces you to a friend or business associate, let them know that you made the connection. Tell them what happened as a result of meeting that person.
When someone refers you to a prospective employer or client, let them know that you made the connection. Tell them what happened (if anything) as a result of this introduction.
In short, if there’s some way someone helped you, let them know. Close the loop! When someone tries to help you, they want to know if they did. Or didn’t. They sincerely want and need to know how things went for you. It’s the only way they’ll know if they’ve been helpful. The feedback can only help them improve in their willingness and ability to help others in the future.
Most importantly, that person will be delighted to hear from you. You’re telling them they made a difference in your life. So, close the loop. Make their day!