Bilateral Drawing is done by holding your art materials in both hands and using them simultaneously. Designs can be symmetrical or asymmetrical.

Here are some samples of symmetrical bilateral drawing, from simple to complex, using four different mediums:

watercolor, marker on whiteboard, acrylic paint, and oil pastels.

Watercolor
Double Doodle Face 93/100
DD Acrylic Painting
DD red heart w/gray

Bilateral Drawing can also be done asymmetrically. Both hands still work simultaneously, but they operate a bit differently from each other. Here are some asymmetrical bilateral drawings.