Create a page or location on the app or within a website to explain/define the clairs and/or mediumship. I've found most people do not know what the clairs are or how they work. Additionally, they do not know the difference between a mediumship reading or a traditional psychic where one seeks guidance.
This would help empower the client while also assisting them in narrowing the scope in what they are looking for in their reading.
You could add a list of suggested items such as photos of people or objects that help facilitate the flow of energy and expedite the reading.