Only a limited number of people are authorized by law to prepare real estate contracts for you, among these are real estate brokers or salespeople (i.e. Real estate agents). If you are not working with a real estate agent, you are entitled to prepare the contract yourself. This is rather risky, however, as there are many issues and concerns that should be addressed in a contract and the failure to do so might well lead to substantial difficulties in the future. Instead, you should contact your attorney to prepare the contract in accordance with the terms and conditions you decide.