You may have to do several favors for each one whom you'll get back, which is like planting seeds. You're probably wondering how you're going to find enough seeds to plant with all that wind blowing. Here are some suggestions:
Help Others
When you meet someone for the first time, someone who you are interested in making business connection, ask questions to find out whether you could help to sovle particular problem for them. Probably you'll learn that the person is having a difficult time figuring out how to launch a new product in your industry. When you go back to your office, find some helpful information and send it to the person.
Get Others Informed Of New Opportunities
When an executive recruiter calls you, and isn't offering you the job you are interested in, refer the recruiter to as many qualified candidates as you know. Although others aren't looking for jobs, chances are that they will be honored you thought of them. You'll do double duty, indebting both the headhunter and the people you have recommended to the recruiters.