If you’re not making money in your sleep, you’ll have to work until you die, Warren Buffett says. One agent provides tips for retiring well.

If you’re approaching retirement age, now’s the time to decide if you have a book of business worth selling to someone else.

If your business consists only of you and your list of past clients and contacts, you might not have anything to sell. Your best bet in this circumstance is to bring in a younger partner and let them gradually take over your book of business, said Duane Duggan of Boulder Property Network in Boulder, Colo. He gave tips on retirement and selling your practice on Saturday at the REALTORS® Conference & Expo in Boston.

By handing your contacts over to a partner, Duggan said, you can generate referral fees for a few years to supplement whatever other retirement income you have. It wouldn’t be a bad idea to invest that money in real estate. It’s an asset you know, and if you get enough properties in your portfolio and manage it well, you can have rental income coming in for years.

If your real estate practice includes more than just you—maybe you have a team or even a joint venture arrangement with a mortgage originator—you now have a business that someone else might want to buy. There are many ways to structure a selloff of your business since it’s unlikely a buyer will have the money upfront to pay you. One way is to get some cash—maybe $100,000, depending on how extensive your business is—and then set up a payment plan for the rest.

If you’re at the stage where you actually have a business to sell, you might consider working with a brokerage or consultant that specializes in the sale of real estate practices. Duggan mentioned eXaltPro and EDI Enterprise Performance Group, among others. REAL Trends, which many in the industry are familiar with because of its news services and conferences, also does valuation consulting for real estate businesses.

Whatever you do, consider making real estate investment part of your retirement mix because you know the field and it’s a way to bring in income when you’re not working.

NAR has a new resource called the Center for REALTOR® Financial Wellness, which has a calculator to help you gauge where you are financially and what you’ll need to retire. It also gives you tools to help you shape your retirement plan.