Mindfulness is awareness. Externally, but internally as well. What are your motivations, and concentration on. One side of mindfulness I’m passionate about is the philosophy of Stoicism which is about living a focused life.
Are there habits in your life that if you do them you are happier, healthier and more productive? Those are keystone habits and they are worth identifying and nurturing in order to live a more rounded life.
Marie Kondo's "Life-Changing Magic of Tidying Up" invites us to ask a simple question of our possessions: "Does this spark joy?". Understanding if something sparks joy can take patience and practice - and has taken me years (so far).
Without realizing it, I had slowly become more judgemental of others. This was negatively impacting my relationships without me even realizing it. This is how I realized this was a problem and started action to do better.