Use simple language that accurately expresses your agreement with the other party. Don't try to sound like a lawyer, and don't complicate things unnecessarily. Define any ambiguous terms. There's a classic contracts case in which one party contracted to sell chickens to the other party. To avoid such misunderstandings, define any terms that may be ambiguous.
Terms of art are words with specific meaning in the law.
Don't use the word in its other meanings or you will create confusion. Use Terms Consistently. Legal writing is not creative writing. Pick one term and stay with it throughout the contract. A New Way To Study.