Individuals with spinal cord injuries (SCI) can have multiple cognitive and physical disabilities because of their injury. Appropriately-designed technology can be empowering and transformative for this population. Unfortunately, just like most technologies, user-centered research methods do not directly account for differing motor and communication abilities. This paper synthesizes SCI literature and leverages our own experiences in three research projects spanning five years with SCI users to highlight significant challenges that HCI researchers might face while employing user-centered methods with this population; communication disabilities, motor disabilities, and difficult contextual or environmental factors can make it difficult or impossible to use standard HCI methods when working with SCI users. We conclude with a set of guidelines and challenges for the HCI community to consider, which can be used both when evaluating papers that work with this population, and to fuel development of new methods or approaches that better-serve them.