How does virtual information fit into the physical world? Mixed Reality (MR) can allow incredible experiences that connect to our physical context and leverage our natural ability to process spatial/visual information, but it can also present an overwhelming barrage of information and contradictory interaction metaphors. Drawing on experience designing applications such as robotic surgery controls, MR hardware designed to engage non-users, and meditation applications, this talk will introduce some of the key challenges and approaches to designing MR experiences including maintaining user focus, mixing Virtual UI into physical spaces, and creating positive interactions with non-users.