We start creating Userflows by thinking about our Personas goals and motivations. Ideally, by conducting User Journey Mapping, Storyboarding and writing Scenarios, we already know at this point what tasks we have to concentrate, what problems should be solved.
Userflows are made of steps. To design these steps in a user friendly way, we need to have a user-centered mindset, and imagine that the user and your interface is having a conversation. To every user-input, the system responds with something. Sketching is a great way of designing Userflows, and we also use a shorthand technique developed by Ryan Singer, which only utilizes texts and connector lines.