Education, family history, social networks, material possessions, learned philosophies, learned habits and/or skills, all appropriated and adopted through the physical body with the physical senses. There is observed sense of "individualization" based on a person's ongoing establishment of personality(ies). The sense of the "individual" stems from the premise - and apparent observation - of a mechanical universe. Most commonly we find ourselves working to define our character, our place, and our role in the world, refining or modifying aspects of the personality and physique to suit our perceived image of our ideal self.
This mode of individualization is hollow at its core, devoid of life and resulting in a mere sum of influences adapted and adopted from the perspective of all other received influences. This topic comes up amongst artists - is there any truly original art? Music? The colors we use are based on colors we observe in nature. The shapes we draw are shapes based on forms we see in the world. Similar analogies apply to music. How can we truly claim originality, individuality, when all we are working with is an amalgam of influences?
The claim of "individuality" derived from such methods of influence can only be seen as a confluence of forces, no room for free will or a true individuality. This claim of individuality is a direct result of placing identity in our thoughts, feelings, and actions, which is only the surface of what it means to exist. Said model is a natural conclusion if we are to be taken as machines, analogous to a vehicle. We can add parts, change parts out, remove parts, change the paint to suit our fancy. Before the vehicle was built it existed as various pieces to be assembled based on blueprints drawn up by a team of engineers. And they borrowed and modified, perhaps even refined, the principles of prior engineers. The result is a machine that does exactly what it was built to do: function mechanically.
The fallacy of this model becomes apparent if we take moment to reflect, as we can see that we can stop thinking, and still be - we can stop feeling, and still be - and also stop "acting" and still be. There is a consciousness behind all of this that ties the experiences together, that remains an observer to all the changes of the body as it grows, all the changes of thoughts (and there are many!) from minute to minute, all of the emotions that rise and fall like the tides of the ocean. The model breaks down completely with respect to the mechanical vehicle - there is not an individualized consciousness through the process of construction through to operation of a vehicle, despite modifications or embellishments.
Truly individuality can only be developed in an abstract sense - abstract in relation to mechanicity. We can clearly see that two people can obtain a near identical education, train for sports in a nearly identical fashion, etc, and yet still have great variation in their vision of existence. Granted many factors are at play - genetic inheritance, familial and social inheritance, etc, a variation that plays out over the millions of years we have been reproducing ourselves. However the true cultivation of a personality cannot result from any amount of addition or modification to the personality, given the factor of consciousness.
A true cultivation of individuality can only result of a much deeper reflection - a break from mechanical adoption and adaptation. We must peer inside, behind our thoughts, feelings and action. Find the mechanical forces that bind us to repeat, like parrots, what we have mechanically absorbed through routine mental, physical, and emotional programming. No amount of academics can change a person's reaction to anger, lust, tragedy. Only when we can understand, in a deep and intuitive sense, the fundamental workings of the persons we find ourselves occupying, can we truly begin to individualize them.