A commercial lease is a long and complex document, and negotiating one can be daunting. Even if you are a strong negotiator, don't try to go it alone. A good broker is essential, because he or she will know what landlords in your area have been offering to lure tenants. And, because brokers have conflicting loyalties, you will also need a lawyer who knows commercial real estate. Your first order of business is to negotiate the term, or duration, of the lease and the rent you will pay, which is usually figured per square foot. Be aware of which expenses your landlord proposes to bill, particularly as part of common area maintenance. Also, be strategic in setting priorities. Here are things to keep in mind about brokers: 1. Listen to your lawyer. 2. Trust but verify. 3. Don't go it alone. 4. Make sure your broker has experience in your market. 5. Keep your options open.