1. Repeating an element in a specific sequence. Creates a rhythm.
pattern
Repeating an element in a specific sequence. Creates a rhythm.

2. A unit or design that can be repeated to form a pattern.
motif
a distinctive and recurring form, shape, figure, etc., in a design, as in a painting or on wallpaper.
A unit or design that can be repeated to form a pattern.

3. contrast
the relative difference between light and dark areas of a print or negative or piece of artwork.

4. value
a. degree of lightness or darkness in a color. b. the relation of light and shade in a painting, drawing, or the like.

5. empty space, space around an object or form; also called white space
Negative space
empty space, space around an object or form; also called white space

6. shading
the representation of the different values of color or light and dark in a painting or drawing.

7. Basic forms
Three dimensional forms that are basic to most other construction are the sphere, cone, pyramid, cylinder and cube. Also most artists recognize organic forms.

8. Basic geometric shapes and organic shapes