The best projects start with a clear brief. You don't need design training to write one — you just need to be honest about how you live or work, and what "done well" looks like to you.
Start with function. How many people use the space, and how? What frustrates you about it today? A designer can solve problems far more effectively than they can guess at preferences.
Then set the boundaries: your budget range, your ideal move-in or opening date, and anything non-negotiable. A realistic budget shared early is the single most useful thing you can offer.
Finally, collect a handful of reference images — spaces that feel right to you. They communicate tone faster than any adjective, and give the design a clear starting direction.