Picking the right interests is huge, and then being able to structure those correctly is what makes the difference of whether or not that audience will work. Use the "Audience Insights" tool inside of your Facebook Business Manager and search for similar brands.

Make sure they sell similar stuff to you, and take note of all the good ones that you find. You are going to want as many as possible, but are only going to be using a few (as you will see in the next video)