Before I begin, I like to get all the requirements of the project. Why are we doing what we're doing? What is the problem we're trying to solve? The timeline of the project etc.
IDEATE and prototype
After I know all the requirements, next step depends on the timeline of the project. If it's something that's not urgent I like to go into exploration mode. Look at designs not even related to the project, go for a walk, get inspired. Work on ideas generated in collaboration other designers or stakeholders. Sketch ideas on paper and digitally. Once worked, put them into Invision App and see how they flow. I'm a big believer in testing before sending stuff to developers.
Analyze and iterate
Once tested, work with the researcher and UX folks on analyzing the results. Based on the results work on iterations.