We will always have a base practice that we can come back to: Compassion/Lovingkindness, observing, and the Five Reflections. This is a base practice. So, if nothing is coming or challenging you at that moment then we know that we can fall back on this base practice until we become aware of what is arising for us at that moment. Certainly mindfulness of what is happening in the practice can help us understand what we are in need of. By understanding ourselves more, understanding our particular personality, then when nothing is arising at that time we can always strengthen qualities or meditations that we know we will be of benefit in our life because of our particular personality.
Say if we're a person who is given to doubt and uncertainty, it can always be helpful to develop a Confidence Inspiring Object. When we're not having anything challenging come up it can be an opportunity to develop those areas of the practice we might not be so strong in. This helps us so that when things do challenge us, that part of the practice can be stronger at those times.
It helps to not think that the reflections are only to fix things. They are also to develop our qualities to a higher level. So doing any of the Unselfish Emotions is going to strengthen the Unselfish Emotions. Compassion/Lovingkindness meditation is always beneficial. So, we don't feel that we have to think there's nothing to do just because we're not challenged at these times. That's why we have a base practice that we can always work on. Often if we go through the base practice of the Five Reflections, something may stand out for us and then we can expand it.