egin by selecting a subject for your subject You might be lucky enough to have someone who will sit for you to draw from life, or you might want to work from a photo. In either case, the most important aspect to consider when setting up your image/model is lighting. You will need to work with dramatically contrasting tonal values (light and shade) when drawing out and carving your portrait, so it really helps if you have a clearly identifiable light source, perhaps coming in from a side/ diagonal angle. This type of lighting can easily be achieved by asking someone to pose near a window, turning one side of their face towards daylight, or you could use an artificial light such as a table lamp.
When teaching beginners, I often also recommend that they try editing their chosen photo using any basic photo editing software (perhaps a phone app) to create a stylised, black and white, high contrast image, like the examples below. This can help you to visualise what a ‘high contrast’ version of your portrait might look like. It is not essential to edit the photo, but might help if you are struggling with the concept of exaggerating tonal values.