I admit to enjoying using both pens and pencils for my drawing work. Both of these mediums are highly controlable though ink work is not easily corrected if you make a mistake…… Therefore, I always “rough” out my subject in a soft pencil before applying the ink.
Another thing I do is leave the work alone after the pencil work, for a while. Its amazing how you can spot any error(s) when you return to a work. Staring at the board for end-less hours, definitely makes you incapable to seeing mistakes……..
It is essential to use a very soft rubber to eradicate unwanted pencil lines and to highlight facial features. Also, brush off all rubber dust with a wide and soft, fan, water-colour brush and then use a hair-drier to blow away all the rubber debrix.