pencil&function

Keep Your Pencils Sharp
Chisel-point or blunt pencils are useful for some techniques, but for most pencil drawing, keep your pencil sharp. Don't worry about 'wasting' graphite in the sharpener - better than wasting your drawing efforts! Brighten the point by rubbing the side of the pencil on scrap paper between sharpenings. If you need a darker line, use a softer pencil, and be aware that a softer pencil goes blunt quickly.
Use a Variety of Line:
When drawing lines, either in a linear drawing or within a texture in a tonal drawing, note that you can vary the weight of the line by lifting the pencil or pressing harder. This might seem obvious, but it is important, and most people don't exploit lineweight enough. Note the example above, which shows how lifting the pencil towards the end of the stroke can be used to give a grassy or fluffy effect. It can be useful to reduce the weight as the pencil is applied at the start of the stroke, rather than dropping it straight into full pressure.
Achieving Even Shading:
A mechanical side-to-side shading motion, with each stroke ending below the last as the hand is moved down the page creates unwanted bands of tone through the shaded area. To prevent this, work back and forth over the same area, randomly varying the spot where the pencil-point changes direction. Or, try using a fine circular motion. This gives a different texture.
Control the Direction of Marks:
Don't let your shading just follow the curve of your arm as you move it across the page. Use direction to describe your object. Follow the form, or create an edge using contrasting direction in two planes. A casual-looking but carefully executed effect of shading everything in one direction can also look effective. Direction direct the viewer's eye or create energy. Even randomness is often carefully considered, in order to look 'artfully dishevilled' rather than 'scruffy'. Where are your marks going?
The Art is in the Mark:
The marks you make on the paper are like the notes played by a musician. No matter how good the written music, if the 'notes' are carelessly played, the result will be ugly. Likewise, by thinking about the kind of mark on your paper, you can make your idea as beautiful or dramatic as you choose. Is it a lyrical, gentle, flowing idea? Let your pencil strokes reflect that feeling. Often the subject (a spiky dried flower, or a curving vase) or model (a wrinkly older person, or a smooth-faced child) will imply a certain kind of handling. Take a critical look at all the little marks you make, as well as your overall composition. Those marks are your notes. Make them sing.

or detailed, realist graphite pencil drawing, you need a sturdy paper which will cope with repeated erasing and working, and a fine texture which will allow you to create the illusion of surfaces like glass, metal or skin. Most drawing paper has a coarse texture which works against you.

For graphite drawings with a moderate degree of realism, a drawing paper like Strathmore Series 400 will give good results without breaking the bank. It's an off-white though, so won't give the snappy highlights you need for very crisp realism. For tonal drawing, especially with lots of darks, it's worth paying the extra for some Stonehenge paper. While its soft surface doesn't take to lots of reworking, the fine velvety tooth holds the medium well.

Many professional artists opt for bristol board, rather than paper, for their realist tonal drawings. The surfaces are strong, tough and very smooth. A plate finish is good for very fine detail and precise lines, while a velours surface will allow richer darks, but can have some visible texture. It's a good idea to try both to see which suits your drawing style. You can't go wrong with a plate finish Strathmore Series 500 Bristol Board.

Another popular option with realist artists is hot-pressed watercolor paper. Some have too much size and are slippery, but a minimally sized watercolor paper will have an excellent tooth and smooth surface, without the slipperiness of Bristol Plate. This is my personal preference too. Try Fabriano Artistico Bright White or Arches Bright White hot press.