i know it has to do with the lighting stuff but still, how would you know, its too confusing?
Well depends on what you are drawing. Light hits different objects in different ways and depending on the intensity of the light depends on how the values will form. I think looking at grayscale pictures and observing real life are the best ways to see how values form. If you are just sketching from your head though it can be more difficult. You need to choose a light source. Say you drew a face and the light is coming from the upper right in front of them. You will shade the cheeks as if they were spheres and nose more as a cylinder. Its a pain and takes alot of practice. Maybe i could put up some pictures so you get a better idea.
Yeaaa it is quite confusing and hard to explain. Whenever I sketch (pencil or charkoal) I tend to make an outline of a rough sketch first, then darken the lines where I see would be the most common sense to make a natural apparence. Yes, it's about lighting and where you want the light to be in the picturen you need to imagine it and smuge in the shading according to the degree of the effect you want. Takes practise and it's hard to get at first, but practise and see what appeals to you :)
Well yeah lighting. But i sometimes get lazy and shade to emphasize the parts of the photo or person that i want to. If its a person you want to shade the nose on which ever side is the shadow, and definatly the cheek bones.
alright i'm no drawer or artist but i like to draw when i'm bored and this is what i usually do to shade. i kinda ooutline with dark pencil and use my thumb to rub around my drawing to shade. its fast and easy.
Please do! I've been wanting to understand this since I was 12.