It's critically important to clearly identify what you do so that others can refer you when the opportunity arises. I have 75 referral partners and I'm not always in front of them to let them know what I'm working on nor am I always on top of what they are working on.
It is my responsibility to convey my latest and greatest ideas and projects to partners -- rather than wait for them to come to me.
Know what you do, and who your ideal target client or customer is.
Let others know this. If they are clear, they WILL recommend you. If they don't get what you do, they won't.
Example: I make a living assisting high powered sales teams to success. I do this in several ways by implementing a simple, fail-safe sales process methodology with various tools. For behavioral change, there is time involved so any training done is followed up with some ongoing coaching. I don't just do training - that is just one aspect of half a dozen service offerings. I'd like people to think of me as a "hub" of sales knowledge - if I can't offer a selling-related service, I turn to one of my 75 referral partners.
The best prospects for me are companies with more than a few sales reps on up to a Microsoft -- who are involved in business-to-business selling -- predominantly in technology, professional services, manufacturing, and other b-to-b markets in the U.S.
Collaboration and partnering is great - be a good referral partner by communicating what you do.