Write or type up the date on the agreement to establish an effective date. List the parties involved in the agreement, using full business or individual names and titles. For example, you may title your business as the "Service Provider" and the customer as "Customer."
You may want to have an attorney review and make suggestions on a template of your business contract. An attorney can pinpoint issues for your particular business that you may need to include in the agreement. You can use a business agreement template and modify it to fit your needs, rather than writing the agreement from scratch.