Flat drawings aren’t usually a product of laziness, but rather a lack of understanding for how an object rotates. A novice might carefully trace an apple, a mug, or a book, but the drawing will still appear as though it is pasted to the page. This is because the eye perceives the outline while the solid drawing depends on observing the mass. If you wish for your drawings to become more convincing, you first have to think about a shape in space rather than its surface texture. An apple is not a curved perimeter. It is a round form with a top, a left side, a right side, and a bottom that turns away. A cup is not simply two vertical lines and an ellipse. It is a cylinder with a direction, weight, and volume. The easiest method for training this is to draw simple shapes before objects.
Draw a cube and see the front, side, and top planes; a cylinder and notice the elliptical side planes and curved surfaces; or a sphere and notice how a round form turns instead of changing direction at an edge. Pick up a pencil and a light source and put one simple item on your desk. Reduce the item to the nearest simple solid shape. The candle is a cylinder. The carton is a cube. Lightly draw that solid form and then think: Where does the light strike this form most directly? Where does it begin to turn away? This is the crucial question rather than an embellishment.
The instant you recognize that turning, you will sense your object as a solid shape. Another common pitfall is applying shading before you have a convincing form. A dark patch might feel powerful, but it does not save a form that is tilted in an impossible angle or has uneven proportions. Furthermore, shadows should not be treated as gray areas floating around the shape. Avoid blending until your form feels secure. Lightly fill in your major light and shadow shapes as separate, distinct shapes. For example, the shadow area of a sphere should curve like the surface, not appear like a sticker glued to it.
For a cube, one plane might be slightly darker than another, but both planes must feel flat. Viewing your shapes as a part of your form (rather than a decoration) can help an object start to look like a three dimensional form on a flat piece of paper. If your object still appears stiff, notice the borders between light and dark. A form that is rounded typically has an incremental shift in value, whereas a form that is angular has a more dramatic shift in value. This does not mean every object must be blended. In fact, over-blurring can be destructive for clarity. Instead, shade using your strokes as lines that follow your form.
Your pencil marks should travel in a slightly circular motion for your cylinder or be straighter for your cube. Doing so will help your hand draw a three dimensional form rather than only a value. If you are finding it challenging, stop shading and run your finger through the air following the surface. This can help you recognize the turn of your form as you are drawing it again. Spend fifteen minutes working on this. Dedicate your first 4 minutes to drawing an imaginary cube, cylinder, and sphere that is large enough to see their direction in space. For the next 5 minutes choose an item in your room and reduce it to one of those 3 simple shapes. Spend four minutes filling in the big shadow areas without blending.
For the final 2 minutes you can look back at your work and the object itself and make one change to the form, not to the details. This is important as many beginning drawings are often filled with small changes while the form remains awkward. Understanding the shape of your forms will make the detail easier and much more convincing at a later time. Things start to appear in reality on paper when you begin depicting how an object takes up space instead of the shape of its edges.
You can work at this skill for years, but you need not tackle complex compositions. A salt shaker, a mug, and a wrapped box will be more effective for learning solid form than an intricate scene full of details. Repeatedly sketch the same object from several different angles and notice the way the elliptical rim opens as your mug moves up and down, and the way the rectangular plane narrows when your box is turned. These tiny notes add to the foundation of strong drawing skills. The page will seem no longer two dimensional when your objects start to feel three dimensional, even when you are drawing simple objects.