This was a classroom exercise which I set for my drawing classes, and not only was it a very good way to develop pen skills, but also a fantastic subject to draw.
I drew a pencil line drawing first, using an F and H pencil. The angles of the table and the legs did require some measuring so I used a ruler to ensure the angles of both matched, so I do not change the perspective of the legs in relation to the perspective of the table. The pattern of the ironwork frame was great fun to complete, and I did use some artistic licence as to the pattern involved.
When drawing always evaluate the scale you are going to make your drawing in relation to the size of the paper. The optimum way, I believe, is to scale the subject matter up so much that the negative space on the paper is far less than the positive space the subject matter takes up on the paper. If you have any problems with this sort of scaling, draw an inch border around your paper, so you do not draw too near the top or other edges of the paper.
Once my line drawing was complete, I started shading, and used a 4B, 6B, 8B and an onyx pencil. Onyx pencils have a sheen to them that works well with shiny type objects.
I put in the darkest areas first, as I find this helps me adjust the values between 0-10 with more ease. I do not always work light to dark with drawings for that very reason. I always use watercolour paper for my drawings, as I find the texture adds to the quality of the drawing.
This drawing took four hours to complete, a perfect way to develop your pencil skills.