Draw upside down
Nope, I haven’t lost my mind – drawing upside down helps you to ‘unlearn’ the bad habit most of us have of drawing what we think we see, not what we actually see.
For example, when drawing a portrait, children will often draw long hair as two strips either side of the face. Unless you have an unusually dodgy haircut, they are drawing what they know about hair rather than looking at the way it really is, i.e. it falls behind the neck, partially covers the face and shoulders, and so on.
The next time you are drawing from a photo, try inverting it. The new perspective it gives will help you to be more accurate. (read: Struggling with a Painting? Turn it Upside Down!)
Similar to drawing upside down, frequently checking your drawing in a mirror will refresh your perspective and help you to see where you are going wrong. For example, when I check my portraits in the mirror I am looking for an approximate symmetry in the face; an oversized nostril is much easier to spot when you see it in reverse. If you need proof that it works, Leonardo da Vinci used this technique himself!
If you struggle with light and shade, get some modeling clay and mould it into the shape of your subject. It doesn’t have to be perfect – the idea to help you understand its shape looks from all angles and how the light source bounces off its surfaces to create shadows and highlights.
Drawings are flat, but they needn’t look it. Turn your drawing into a map using contour lines – lines that indicate gradient. For example, if you were drawing a face, the ‘highest’ point would be the tip of the nose, so start here with a small nose-tip shape, then move out using expanding shapes. Lines close together indicate a steep gradient (e.g. the nose), while lines far apart indicate a gentle gradient (e.g. the cheeks).
If you were asked to draw an elephant, where would you start? With the trunk? The ears? It is common to want to hone in on the details straight away, and while there is nothing wrong with this, by starting small you risk running out of space later on. For this reason it can be helpful to block out the drawing first using big, rough shapes. The elephant has powerful shoulder muscles, a huge head and thick legs, so these are what I would quickly block out first, before refining the shapes further and then moving on to the details.