First, let me just say, I find noses hard. As with any piece of detailed drawing, Noses can prove difficult for anyone. There are so many shapes to consider, it can seem an impossible task. Try not to worry, I will try and explain what I do as simply as possible, and break the whole process down into simple terms. As with anything the first thing to do is to look past the nose, to the shapes and tones. It is these that will create both realism and emotion in your drawings. All of us need inspiration at times, and with the nose my first piece of advice would be to collect as many photographs sketches and drawings of as many different noses as you can. I would also try to collect some images of the structures of the nose; these can help you understand how those shapes fit together. Here are some amazing pictures for inspiration, with some ideas to try and help you and some talk of the lessons I have learnt myself.
As you can see from the sketches here, if you look at the final drawing, it looks complex and very detailed, but instead of looking at the whole image, start to separate it off into the basic shapes you can see. I was once told by an old art teacher to try turning the picture I was trying to paint from upside down to try and see beyond the image itself. It worked remarkably well for me, it may do for you too.
You can start anywhere, but imagining the basic shapes is the best place to start. This is just a preparatory sketch and there will be mistakes, don’t worry, just think about the various shapes and how they fit together. Once you are happy with the basic shape, look at how the circular shape of each nostril fits into the basic triangular shape of the nose. You can begin to create some depth by emphasizing the various curves with light shading. Although you may see the vague shape of the nostrils, much of their shape will be created by the variations in shading, Pick out the darkest areas first and as you work you can gradually overlay more areas of shading. Keep it simple, building up the shading to create the shape means you can overlay lines of shading, emphasising the curves and creases. Introducing the curves and lines of any folds of skin around the nose will give you chance to experiment with expression too. Always look at how the light creates shape with shadow, this will give you the depth of expression needed. Lastly, as you add the finer details, you can add any final shading around the nose. If you imagine a ball sat in a shallow hole, wherever the light source is the shape is created by the shadows, use those shadows, they are your friends. You can see that at times I have used very light pencil strokes in the initial sketch, knowing they will be overdrawn or erased in the final image. I use a very sharp pencil in places, to emphasise the shape of certain parts of the image. Then, as the picture develops, I often use a much rounder (more blunt) pencil tip, to soften the image and create depth. Using different pencil grades can help with this. In general I start with a fairly sharp HB grade, use a 3B to emphasise the darkest areas. Use a very sharp HB for finer details, and then a much rounder tip HB and 2B to soften the image and create the gradient of tones within the shaded areas.
You will be amazed at the subtle differences in shape and tone that can help you create expression, as you look at, and draw, different noses from the reference material you have collected, you will begin to see how those shapes can help you create more lifelike and expressive drawings. This will bring your artwork to life. The nose can be the most striking part of a face drawing, and time spent here can make the rest of the face much easier.