Do not get attached to the chosen means and keep testing it (in coordination with each other) for its intended purpose.
Already in this phase, involve stakeholders you will encounter in the following phases.
Be happy with failures. You can learn from them.
Accept that the swamp of trouble is part of it.
Combine data with stories.
Try different search paths.
Ensure diversity of sources, expertise and experience.
Seek assistance from stakeholder circles.
Agree beforehand on what is enough.
Take time to reflect on the process.
Communicate about the journey of discovery and not just the outcome.