Step 0. Process, People, & Plan...
I know design thinking has 6 steps.  I like to distill it into 4 steps, further defined by a problem space and a solution space.
As UX designers we love research.  Jared Spool states it perfectly.
Business objective:  
How to document a problem in a manufacturing environment?
A batch record is where all information on a manufacturing lot is recorded. 
The Stakeholders...  
"People over process."
The Experience Plan
A good experience plan is essential to align the level of effort to the problem,
Step 1: Discover Phase
Goal: Understand the problem
Workshops
Let's get it all out on the table. Step 1, document business objectives and assumptions.
Hypothesis
With assumed information, we can align.
Create a space to collaborate
Whether in a conference room, FIGJAM, or Miro. 
Internal Research
Before involving users, let's use internal SMEs to kick the tires of our research study. 
eth·no·graph·ic 
The study of people in their own environment through the use of methods such as participant observation and face-to-face interviewing.
Our favorite, face-time with users.  In this case 4 cities in 4 weeks.
Plan Ahead to Trend
Without trended data, we're just another opinion.
Step 2: Define Phase
Goal: Understand the validated problem
The Problem
After good ethnographical research, we have a validated problem statement!
Persona
Love 'em or hate 'em.  It all starts with a person.  
Journey Maps
My favorite way to display synthesized research data.  Vectors of emotion are genius.
The Learnings
Data showed we had 3 problems to solve, not just 1.
Step 3: Design Phase
Goal:  Identify the optimal solution.
This quote forever changed me as a designer.
White-boarding
Expo marker might be my favorite tool.  It's definitely the cheapest and fastest 
prototyping and collaboration tool.
Workflow Diagram
Let's make my whiteboard easier to understand. 
3 small initiatives rather than one big one giving users value faster.
Information Architecture
Let's continue to refine the solution.
Step 4: Delivery Phase
Goal: Get the optimal solution in the hands of the engineers.
The Tools
We've been around the block.
Validate the Solution
The Validation Script
I've been lucky enough to be mentored by some really good researchers.  
Because we did our homework, research was quick and easy.
Synthesis & Marketing
The Result