I consulted with someone in this space. He was extremely knowledgeable and could answer questions quite professionally. It was my recommendation for him to focus on speaking engagements. Many groups are looking for people to come in and speak. If you are experienced in, and knowledgeable about, health insurance and can conduct a good Q&A after your speech it won't take long to carve out a reputation for being an expert in the field. Your phone will start to ring with requests for you to come speak.
1. As Charles Alexander suggests, speak on the topic to businesses—offering value about what to look for and what pitfalls to avoid.
2. As you get clients, offer them value. Don't just be a broker who matches them up with an insurance company/plan and then goes off. Instead, be proactive with following up with them, be a point of contact for problems, approach them with new info when some policy, etc changes.
If you appear to be a proactive insurance consultant who looks after his clients, then you will stand out among average brokers, and get referrals.
Act as a customer - I work on the medical insurance side and frequently interface with large insurance broker and consultant groups trying to gain visibility of our product so they sell it. Some of the larger brokers are Mercer and WTW. Have you considered working for one of them for a while to see how they generate leads? It seems most of them have a formulaic approach for generating leads and work closely with insurance companies to ensure the product they sell is what employers want. You could also act as if you are a customer trying to buy insurance and see how existing brokers connect with you, ie online, networking, conferences.