Draw.
(From fr. ant. deboissier).
Drawing is the basis of all graphic creation, from design to great pictorical artwork. Every work starts with a drawing, a concept drawn on a piece of paper. It is very important to be able to translate the own ideas into paper. The main goal is reached by fulfilling this difficult task.
Good drawing leads to good artwork, so it is critical to gain knowledge about anatomy, perspective, etc. The study of the great masters and great drawers (Bridgman, Loomis, Hogarth.) is essential.
The last, and the most important thing to keep in mind, is practice. Daily practice improves your drawings, which are the basis for good artwork.