I began intense concentration practices earlier than i can remember. by the time i was 11 i had achieved extreme dexterity and hyper focussed visual observation.
 
It wasn't until i was well into adult life studying the nature of conciousness and meditating that i realised i had spent most of my childhood in deep meditation, as most children probably do. 

basically drawing is archery except one hits the bulls eye with a pencil instead of an arrow. body-mind is trained to be extremely still while aiming. ancient Japanese archers and craftsmen even went on special diets to maintain it. 

my intense visual concentrations often moved into a natural resting state where the eyes would focus on one line until it dissappeared and a blissful stillness became an open eye, not seeing meditation lasting up to 30mins sitting in a chair, undisturbable by siblings.       

three basic abilities are trained to draw precision reproductions of 3D images as the human eye sees them. all require exquisite concentration and equanimity, as the tendency to lose patience at such a young age has to be overcome. 

The 1st skill to be trained was manual dexterity which began by copying 2D images (comics). the earlier that manual dexterity is achieved the sooner it becomes permanent. no further training is then needed as it doesnt deteriorate with age unless the motor neurons do. but visual perception and the mind's eye, never stops learning.

Next came the rendering of 3D perception. for this training the visual cortex had to ignore the complete picture and see in minute detail the many abstract shapes (which include the shapes of empty spaces) that make up the 'appearance' of 3D forms. ancient artists couldn't discern these shapes so visual perception and color memory in modern humans will probably continue developing.  

Next came 'the honing'. the innate measuring skills of the visual cortex (which can be amazingly precise) mentally measure those many abstract shapes then recombined them in their correct positions. thus a 'whole 3D image' without distortions can be rendered. hand-eye cordination has become one. 

this is not something 'I' did or achieved. brain simply exercised it's innate ability to overcome it's neural limitations. nature then drew itself. the choice of skills to excel at is influenced by familial and cultural exposure.   

drawing what the eye sees requires ignoring what one feels and thinks one is seeing, as they cause visual distortions like Primitive Art or 2D Egyptian art. feelings and thoughts distract the eye from what is actually apparent. eg that a foot facing forward is foreshortened doesn't make sense to the 'feeling eye'. only by concentrating on the abstract shapes the retina sees can the actual 3D image be reproduced.  

once these skills are learnt one can draw anything and go into any profession requiring extreme dexterity, from carpentry to surgery. although most in those professions don't achieve it so machines compensate.

creativity comes in when thoughts and feelings along with preferred colors and compositions are reintroduced with intentional distortions (elongated bodies etc) or complete abstraction. but precision drawers can maintain artistic integrity even in abstraction in a way non drawers cannot.

high precision drawing of what actually appears to the human eye enables one to produce more intriguing futuristic or idea-less imagery. thus Piccasso and most masters learnt it first. 

learning to draw to a photo-realist degree utilises the same mechanisms and drives that all skills utilise whether it's mastering a skate board or a violin etc. configuring the neural connections required to excel in any skill is best trained young as the neurons lose neuroplasticity and spacial connectivity with age making it impossible to learn hyper dexterity in maturity. no one (on record) has ever learnt it as an adult. but one can still express a high level of creativity at any age with color compositions and distortions or total abstractions, which is what most artist who didn't have the temperament (patience and concentration) to learn extreme dexterity in childhood, resort to. 

Adults who concentrate to this degree in early childhood meditate easily. I don't as a separate practice. i naturally meditate on everything i do.