"Once the most promising students have been selected, they then continue to be taught for up to a week before they are considered ready to make a living from it.”
They are taught by first showing them how to hold the paintbrush. While some curl the trunk around the brush instinctively, the preferred method at the Center is to hold the brush in the ‘nostril’ at the end of the trunk, which gives the artist greater range of movement for the brushstrokes. For this purpose the paintbrush is modified so as to be the right length and thickness to hold easily.

Next they are introduced to the easel and taught how close to stand to it so that they can extend their trunk comfortably. Finally they are guided by the mahout to apply the brush to the paper. Some artists take to this quicker than others, but all of them need time and encouragement to learn how to apply the paint within the confines of the paper, to know when the paint has dried up and to develop a style of brushstroke that suits them.

During the training the artist’s natural instinctive style becomes evident. No two elephant artists have the same style and just like human artists, their style develops and matures over time.

It is quite unnecessary to force the elephant to learn how to paint. Those that do not seem to enjoy the activity are introduced to other activities. Today there are 17 elephant artists at the Center and all of them thoroughly enjoy painting.

http://www.elephantartgallery.com/meet/school/teaching-elephants-how-to-paint.php