Brainstorm ideas for your abstract image. You can create an image straight from your mind without any outside muses, or you can take an existing image and contort it to make it interesting. For example, Picasso took everyday faces and warped them into new shapes using an art form called cubism.
Select a canvas with smooth muslin cloth. If the fibers are too coarse, it can make sketching your design a difficult task.
Visualize your image before you attempt to draw it on the canvas. While you are picturing it, create a light pencil sketch (using a soft lead pencil with a broad tip) on the canvas that captures the basic shape of your abstract design. It doesn't need to be perfect; perfection goes against the base idea of abstract design.
Refine the shape and darken the pencil lines of your design once you have the basic sketch on the canvas. Leave the pencil marks light enough to erase if the need arises. Once you perfect the base outline, you can make the lines bolder and more permanent.
Trace over your pencil marks with a fine paintbrush dipped in black paint. Allow the paint to dry thoroughly and inspect your lines afterward. Retrace the lines if you find some faint or thin spots in your work.