The caricature and the cartoon have been around as art forms for some time. Some believe the caricature originated during the time of the Renaissance and the Reformation when societal emphasis shifted significantly to the importance of the individual. In it’s earliest representations the caricature was generally a line drawing of a person in some type of action, but some of the person’s features are significantly distorted. The caricature is never just a portrait of a person, but rather an exaggerated drawing in which one or more of the subject’s salient features seized upon and comically distorted for a satirizing or ridiculing purpose.
Many will claim that the caricature though distorted and exaggerated must still look enough like the subject to be clearly recognizable as the subject, and in the context of the drawing must also have something to say. These characteristics of the caricature suggest a significant burden come to the artist who tries the form. It is clear that not just any artist can easily meet the demands of the caricature. As much have been suggested by many of those who currently are regarded as successful caricaturists.
Some have thus suggested that the caricature requires more than artistic talent, that you just have to have it within you to do it successfully and consistently. You must recognize the really unique features of the subject. Often that is really obvious; e.g., big nose, big lips, big ears. Then you just exaggerate that feature and everyone sees it as unique but is still clearly recognizes the subject. At the same time other features may change in the drawing such that sinister or other intent may be inferred and seen to be in line with the social or other commentary underlying the meaning intended in the caricature. Observers thus see the caricature in an humorous or interesting or in some other intended way.
To be a successful caricaturists you may need many bad caricatures before you get better or at least good at it. Many caricatures become cartoons, often political cartoons. They offer both political and social commentary in newspapers and often the same or just wit in magazines. They are a version of editorial opinion.
More recently some successful caricaturists have expanded into the cubist-caricature ( as an example see http://www.raycasso.com/about/ ). This is an interesting development as both Cubism, championed by Picasso among others, and the caricature move our art into a new reality.