A great recruiter understands that it doesn't matter what you want or who you think is the right candidate; it's what your client thinks that really matters. You have to understand exactly what they want and the type of person they really like. Skill set and experience is crucial, but so is personality. If you present two candidates to your client and one is 100% on the button with their skills and experience but the client does not like them personally, they will not hire them.
However, if your other candidate is only 80% right on skills and experience but they really like the candidate, there will be a much higher chance of them being hired and trained.
When taking the position description, question your clients heavily about all aspects of the role, including the type of person they like. Learn to listen and understand exactly what they want, not what you think they want. Keep giving them what you want and you will always be looking for new clients.
The Sales you need to be able to close in recruiting is like no other sales profession. We have two sales going on in every situation. We have to sell opportunities to candidates and we have to sell candidates to clients. We have to close two sales to get the one. Both in a sense are customers and both have the one thing that will lose you more deals than any other: emotion.
Most other sales professionals only have to deal with customers' emotions, while we also have to deal with candidates' emotions.