The chapter reviews the importance of paperwork, rapport, and preparation for the assessment. This includes the creation of an informed consent form that covers issues of cost, length and scope, missed appointments, access to testing data, and information sharing. The chapter explains the difference between assessment and treatment. Before beginning an assessment, the clinician must gather essential contextual data, including work history, admissions or hiring information, workplace performance or grades, previous treatment history, and parental contact. The chapter reviews ethical considerations related to assessment and the establishment of the assessment relationship. Techniques to develop rapport include building on similarities, using Socratic questioning, and lowering defensiveness. The chapter explores diversity as it relates to the assessment through culture and ethnicity, sexual orientation, socioeconomic status, and microaggressions, defined as brief, everyday exchanges that send denigrating messages to certain individuals because of their group membership.