NAVA recommends that artists insist on written contracts for all sales arrangements. The Arts Law Centre of Australia provides standard contracts that can be adapted as required. If you decide not to use a formal contract you should at least note any agreements you come to and get the other party to confirm that those notes are correct. The agreement should cover all of the issues and be fair to both parties.
See the links under Establishing a Professional Relationship with a Gallery or Agent for publications which will help you determine the issues a contract or agreement should cover.
