Put a mug, a paperback, and a small plant pot on your desk. Take a look at the forms before making a mark on the paper. That mug isn’t just a mug. It is a cylindrical form with an elliptical opening, a cylindrical wall, a circular base, and a handle (you can think of the handle as a miniature torus). The paperback is actually a rectangular prism with a top plane in view and the edges angled back into space. The plant pot is likely a truncated cone (tapered cylinder), which might look more complicated because of a curved, flared top edge and a cast shadow, but if you ignore the rim and shadow, it’s just a truncated cone.
Simple shapes provide structure for your sketch before the specific outline matters. If you try to replicate every line as you see it without first establishing a shape, your sketch might soon become hard to follow. One side may end up taller than the other, the bottom may appear to tip, or your object may slide off of the page. The circle, box, cylinder, or wedge provides an outline of a plan for how you intend to lay out your composition. It allows you to determine the position of the subject, its general dimensions, and where you should be mindful of the shape’s proportions before darkening the lines.
Next time you draw an object, try a quick shape sketch. Use a light touch and, in sixty seconds, sketch just the major form of the object. Don’t worry about texture, lettering, handle detail, foliage, or shadow. For a mug, you would only draw the main cylinder and the top ellipse. For a shoe, you would look for a long, tapering box shape, and then draw the shoe opening and the shoe bottom. For a chair, you’d sketch the main seat in the form of a box and the backrest as a tilted rectangular plane. The initial sketch should look boring, but should also provide a visual aid to understanding the object itself.
It is very easy for your eyes to begin categorizing and ignore the true form of the subject. Once your eyes see a cup or a book, your brain often wants to switch into auto-pilot mode and just copy a shape you have drawn many times before. This is often why so many beginner sketches fail to convey a sense of three dimensions even though the object is still present before the viewer. By breaking objects into simple forms, you are forcing your brain to slow down. Your brain is forced to consider height relative to width, side edge relative to side edge, and shallow ellipse relative to round ellipse.
Once you establish a simple structure, the contour drawing becomes easier to follow. Instead of guessing an outline, you are actually making a choice about which parts of your construction drawing you want to show. The construction shapes might remain a light drawing, be erased, or be covered over by darker lines. It might even be helpful to draw some construction lines to indicate a shadow or a hatch-mark shape. This technique is especially helpful for objects that overlap or hide each other, like a mug handle overlapping the mug, or foliage in front of the top edge of the pot.
Simple forms also make for a less frustrating review. You can skip a question such as, “I’m not sure what’s wrong with this sketch,” for a question such as, “Is my box too slanted?” “Is my cylinder too skinny?” “Is my ellipse in the right direction?” or, “Is my drawing of this object too high on the paper?” These questions will allow you to focus on specific adjustments in the next sketch without having to erase everything or blame yourself for poor technique.
What you want to avoid is the idea that you can only get a better sketch when every part of the subject is perfectly rendered. What you want is a better sketch when you can see the main form of the object. The more you practice finding circle, box, cylinder, wedge, and ellipse forms within your surroundings, the less confusing sketching becomes. When you begin a new sketch, ask yourself what simple form is the subject before drawing any other detail.