In the instructional design field untrained instructional designers are creating educational content. In these instances, the content is created by subject matter experts. This growing subset of experts is known as instructional designers-by-assignment (DBAs). DBAs are prevalent in the equestrian education field. Unfortunately, in equestrian instruction, inadequate educational experiences can lead to learners quitting, lack of progression, learner frustration, loss of motivation, and serious injuries, including fatalities. In physical education literature, gaps in the literature indicate the need to understand what instructional design best practices a subject matter expert acting as a DBA uses when creating educational content. In equestrian literature, it has been identified that more design literature is needed for equestrian instructors. Using instructional design principles in practice can help practitioners make educational content more effective, relevant, and a safe experience for the equestrian learner. This study used a Delphi methodology to answer the question: "What is the expert consensus on instructional design practices for equestrian DBAs?" During data collection, the expert panelists responded to statements in an instrument during three iterative rounds. The data were synthesized to determine if a consensus was met on each statement. The study's target population was equestrian experts who self-identified as persons who actively create and deliver education to equestrians. To add credibility to this study, the researcher included criteria to ensure that the expert panelists had adequate experience. The study began with 46 equestrian experts within the United States who actively design and deliver education to equestrians. The sample contained expert panelists from English and Western riding disciplines with varying degrees of experience in providing education. By the end of the study there were 37 expert panelists. Data from the three rounds were collected from Qualtrics. After the three rounds were completed, the mean, the interquartile range (IQR), and interquartile deviation (IQD) were calculated for the Round 3 data. Based on the data analysis, a set of best practices was developed. The findings indicate that the equestrian experts, acting as DBAs, use design processes when creating equestrian education. The expert panelists indicated that they use analysis, consider safety, and use principles from experiential and transformative learning theories. There were multiple recommendations for future research identified, which may help refine the identified best practices and possibly lead to a design model for equestrian education. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]