Understand what the requirements are from the project managers/ PLMs, SME's and other stakeholders.
Users: who are they and what they're about? Gather stats, qualititive research, competitive research to be used in differentiating key features.
Make sense of information gathered in terms of requirements of the stakeholders. Here's where the user personas, user flows and information architecture takes place. Wireframing and iteration.
The creative fun begins. I like to take deliverables from previous step and create a couple design alternatives to be used for testing. Lo-fi mockups usually.
Making clickable prototypes for first round of user testing. I will then create hi-fi mockups and prototype those to give a seamless experience using style guide.
Testing is always important because here's where you can validate your design with users and other stakeholders. Usability testing & A/B testing. Iterate until optimum solution is reached.