We have three basic ingredients of art the visual elements, principles of design and component of art. Those three are very important in the elements of arts. For me in the visual element line is important. Line is a series of connected dots. It is important because if you don't have lines you can't create various shapes, designs, segments, letters, drawings and etc. And there are eight kinds of lines. Vertical lines, horizontal lines, diagonal lines, straight lines, curved lines, repeating lines, contrasting lines and last but not the least modified lines.
In Principles of Design the Emphasis or Focal Point is important for me for the others to get the artists message. Give focus to one or more parts of the thing or the whole thing itself. Holds the viewer's eye on certain parts of a work. The focal point is the center of interest or activity in a work of art. It may or may not be the actual center of a painting or drawing, but it is always the most important part. Contrast, structure are three things that help define the focal point. 
And for Component of Art is Subject Matter, subject is one of the most important in arts. Subject matter is what something is about. In artwork, the subject matter would be what the artist has chosen to draw. You need to think first what's your work all about. 
