This is where I believe that certain "natural goods" are important -- such as the need for friendship/companionship (and all the enjoyments that come with it) which can make life situations feel better or less stressful or less disappointing.
The interpretation that I'm currently working with is that natural and necessary desires, such as friendship, are a priority. Fulfilling them is the bottom limit of the sweet spot. Once those are met, there's great pleasure to be had in pursuing a variety of desires, as long as we stay in the sweet spot and below the upper limit that is the vain desires. If the natural and necessary desires haven't been fulfilled, then it's a priority to work with them, although this will most likely be done concurrent with pursuing natural and unnecessary desires. In the process of sorting out all of these desires we determine what, for us as individuals, is natural and necessary and what is the icing on the cake. At least for me, it's a constant work in progress!