Many great answers on this thread
The best marketing I've had has been through handing out business cards and speaking with agents/homeowners. You really never do know where your next referral may come from!
A large majority of my private/non lender work comes from referrals from agents that I have worked with in the past.
This does take time to cultivate and isn't a "quick buck" by any stretch. BUT it always pays YOUR FEE!
Personally, I leave/hand out a business card at every property I go to, including vacant properties (usually leave it on the kitchen counter).
Again, you never know who will be that next referral!
(Edit to add: Good luck to you Center - you've made it this far, keep it up! I'm not much older than you (38) and have "only" been at this for 12 yrs. Hang in there and keep at it. It pays off in the end, but ... it is a PITA to "get there!")