This is a tutorial I used for my drawing and painting students at Ohlone College. (But feel free to use it if you like.)
The sphere, cube, and cone are the basis for a lot of shapes that you will have to draw and paint. I have a PDF that you can download of the basic shapes to print out and draw here.
I start by using a charcoal pencil and I'm holding the pencil the way Humphrey Bogart in those old movies holds his cigarette.
I start by very lightly sketching a diamond shape. Then I take a compressed charcoal stick and use the side of it to draw the verticals. I'm holding it "Bogart" style and I use the longest edge almost like an ice skate to make the vertical lines that drop down from each corner.
Same use of the compressed charcoal stick to create the diagonal lines. Keep everything as light as possible! You want the lines to disappear as you shade in the planes.
Indicate in the background of the table.
The cast shadow is laid out as a horizontal line that starts from the where the corners meet the table top. One of the corners is hidden behind the body of the cube. The shape of the cast shadow looks a bit like a house that's been put sideways.
Now for the moment of truth! I drew everything freehand so if I put a T square against the paper are my vertical lines really vertical?
Nope! They are not straight up and down so I need to fix that.
All better now. Next I take the piece of compressed charcoal and use it kind of like a big paint brush to mass in the largest shadows and planes.
This is a compressed charcoal stick. This is a quick way to fill in the values so that it will make the drawing happen faster. My teacher Irwin Greenberg use to say that "Big painters use a big brush." I think that the same applies to drawing materials.
It's really important to work background to foreground.
Next comes the cast shadow.
Using the eraser to clean edges and also to smudge and blend.
Applying a tone for the tabletop. I guess I really should have done this earlier.
Using a stump to blend and even the tones.
Using a charcoal pencil to make small hatches and define and modulate the values.
I think that mark making is an important part of drawing. I'm using light lines that are parallel to the sides of the cubes to even the tones and create some texture.
At this point this drawing is a finished version that uses mark making. It's important to think about the direction and frequency of marks. Some artists do not like mark making at all and so they completely blend the tones.
Next, I'll show you how to do this towards the end. Here I use the eraser to start doing this and to straighten things out. At this point I'm kind of just playing around to make it different.