Take the first step and start to build the prototype.
Don't procrastinate.
Don't waste too much of time on building a single prototype.
The prototypes must be built with the end user in mind.
The prototype must not beamere piece of trash; it must create an experience for the user.
Think of open questions that the user can shoot towards you when he presences the prototype.
Taker the end user through the prototype and let him/her experience it completely.
Throughout the experience, make the user speak about his/her moment-by-moment experience.
This will help you as a design thinkers to capture the minute details of the experience.
Try to actively observe and enthusiastically engage with the user during the experience.
Once the experience is over, follow up the user who had the experience with a set of questions.
It will be better if the set of questions is not imprompter and is prepared before hand.