Part of laying the foundation for design is defining the why & what for.
Having a set purpose in mind, however high or low, helps to guide the evolution of the experience and to ensure that what you end up with matches your original (or revised) intentions.
Place a copy of your motivations & aims somewhere you will see them as a constant reminder of what you want to achieve. Don't be afraid to revise these as the process evolves.
Why have you decided to create this experience?
What do you want to achieve...
What, if any, outcomes would you like to see as a result of:
How will you measure if you have achieved what you set out to do?
Put it on paper.
Put it somewhere visible.