Art of the Small was a radical and advanced Force method of melding oneself with the Force. Under meditation, a Force user's presence shrank to a microscopic size. While in this state, the user could operate molecules in any way they wanted, turning them into something completely different.
The Art of the Small used to be a challenging Alter-based Force ability among the Jedi Order which was expected to take talented Jedi Knights a year or two in order to become an expert. Through shrinking the Force presence to that of a single atom, it allowed for an unprecedented degree of stealth as well as allowing for a perception of the universe on a molecular scale. Using telekinesis in this meditative state allows Jedi to eliminate toxins and cure certain ailments in others as well as in themselves by constructing healthy proteins and rebuilding cells.
With the power to alter things at a molecular level, a Force-user could have many uses for such a technique.
As demonstrated by Vergere, the failed Sith apprentice who named it, the Art of the Small could be employed to conceal one's presence in the Force or outright render them invisible. Thus, it was not only a unique method for Force healing, but was also another manner of Force concealment or Force camouflage.
Vergere used her powers to give her tears healing properties, which helped Mara Jade Skywalker in combating the coomb spores she was infected with. She managed to teach the art to Jacen Solo and Cilghal. Onimi, jester to Shimrra Jamaane, also had this ability, but his level of control was much greater than Vergere's. He was able to amplify the current of energy flowing through his mismatched form, as well as compose deadly toxins and chemicals, able to be released through almost every aspect of his body; his blood, his sweat, his tears, his fang, and even his curving fingernails. These abilities allowed him to control Shimrra and become the true Supreme Overlord of the Yuuzhan Vong.
Jacen Solo taught the technique to Ben Skywalker, who in turn taught it to his mother, Mara Jade Skywalker. Both used the ability to hide their presence in the Force. Mara described the technique to her husband, Luke Skywalker shortly before her death. Allana Solo also used this technique on planet Klatooine to shrink her presence and follow a powerful dark side user.