Developing a soft and spacious mind — of mindfulness — means developing the quality of acceptance.  For example, suppose you are watching your breath in meditation and you feel a sense of struggle or tension.  This feeling of struggle may be a sign that something else is happening in your experience that you are not recognizing or allowing.  Perhaps you are not opening to some other sensation in the body, some discomfort, or some underlying emotion.  Or perhaps you have become caught up in expectation, with too much effort or striving, wanting the experience of the moment to be different from what it actually is.

Softening the mind involves two steps.  First, become mindfully aware of whatever is most predominant.  That is the core guideline for all insight meditation.  So the first step is just to see, to open. For the second step, notice how you are relating to whatever arises.  Often, we can be with an arising appearance but in a reactive way.  If we like it, we tend to hold on to it; we become attached.  If we do not like it because it is painful in some way, we tend to contract, to push away out of fear, irritation, or annoyance.  Each of these responses is the opposite of acceptance.