The idea of "adding value" to others depends on the idea you have something of value to give them. In order to add value to others in the long term, you have to continue to grow and become more valuable. And to add the most value, you should try to stay in your sweet spot: where your passion, purpose, and potential intersect.
Each of us has a lid on our potential. The only way to life that lid is to intentionally develop and grow. As you do that, you will also become someone who can lift the lids of others: someone who sees the greatest potential in others, and gives them what they need to rise up and fly. Every time you learn a new skill, or overcome a new struggle, you have more to give. As you improve yourself, you can help others improve too.
In his book, Take the Cap Off Your Capacity, leadership expert John Maxwell explains we should always focus on those things we should apply, change, and teach others. When we A.C.T., we move from an internal process of growth to an external process of contribution. This is the most rewarding phase of personal growth, and that is how you live a life that matters.
Give as you grow.