Include the date you've entered into your agreement. Name all the parties involved and provide the official title of each party ( "producer," "director," "owner," etc). Then explain the nature of your agreement. What is your mutual covenant? Try to cite applicable law pertaining to your agreement.
List all the obligations and warrants of both parties. Make sure you're not violating the rights of any third party. Explain who shall be responsible for payments and when. Make sure you're held free and harmless from extra claims, liabilities and costs if there is any breach of contract. However, list all the rights and responsibilities of both parties in the event of a breach of contract.
Make sure that your agreement contains the entire understanding between the parties and all prior agreements are merged into the one that you're writing. Ensure that your contract is not altered in any way by anyone else not included in the agreement in the future. Try to sign all your contracts prior to your production. Have a good shoot!