How about a beginner? Drive a roller
(with chalk and pen in the fixed seat mark, can be very easy to let you know the wheels what need pressure.) no reference straight line can also use this earth way.
In accordance with the operation of the wheels and the road along the road of slowly fine-tuning, go back to see just the pressure line as a reference, a large operation is more simple, first out of a straight line, then straight to the reference.
Specifically how to paint their moving brain, is very simple. When I was 17 years old. No one taught in his invention.
