Portrait drawing and technique

so I certainly have room to improve still, Im yet to meet an artist who doesn't feel that way. For me my favourite is tonal drawing, there's something beautiful about using just pencils. One of my great artist friends Dennis lawson told me as a child you must master pencil before you paint. Boy was he right, by learning tonal drawing you concentrate on the form alot longer, making sure each stroke accurately represents what you see. Without being able to accurately draw your painting is doomed from the foundations. Many skills of carry over also. When drawing you spend far more time studying the subject than you actually do drawing it. What you invision in your mind is quite often very different from the reality. So for any people starting out in art, or with children hugely interested my best advice is to get a good quality set of pencils, and sit and try and draw things like spoons, fruit etc accurately. Really concentrating on where the shadows and highlights lie and all that's in between. With alot of patience and practice you'll slowly see your work improve with each drawing.