User Personas and Empathy Maps are a vital and crucial aspect of my design process. I always started trying to understand as much as I can from my potential users applying the resources I have to collect data and insights before I create these documents. If the project/budget/client allows you can do magic, talking to people in focus groups, one on one interviews or getting tons of data and analytics to review and analyze. Sometimes we don't work in that "user research paradise" but there's always chance and resources to know and understand your users, no matter if you start collecting data through an online survey or even doing Skype or phone calls. I'm working on some freebie Sketch templates for designers to easily create personas, empathy maps, and user journeys.