At the agency I started, we tackled this by working toward higher visibility in the industry. For example, when I was growing the agency years ago, I wrote articles for sites like Smashing Magazine, Nettuts, CSS-Tricks, and so on — this granted authority and presence to my agency.

Then, my team and I started attending (and, ideally, speaking at) conferences wherever possible. Again, this lent us authority and presence.

In both cases, we were putting ourselves out to the community at large as a professional agency with deep expertise that was capable of handling large projects.

This alone led to inquiries from several agencies, which was great: we had effectively manufactured a referral network for ourselves by writing and speaking.

After that, we started attending local design meetups and events. I'd seek out agency developers, product managers, producers, and anyone with the title "technical lead" from the larger agencies, and then — WITHOUT PITCHING ANYTHING — I'd try to get to know them and hear about their problems, and I'd share anything I could to help.

Word got out that my company was friendly, helpful, and not just trying to work angles for contracts. And as a result we landed a lot of contracts from agencies, and regularly booked $50K+ projects.

It's not exactly a quick formula to follow, but that good will has followed me AFTER I sold my company, and I'm still working with fantastic companies who seek me out — so while it's not fast, it's a very sustainable approach.

I'd be happy to discuss specifics with you and help you lay out a concrete strategy if you're interested.

Good luck!