I start sketching with a pencil and rub the drawing out a few times with a paper towel at different stages. This allows me to rub out areas I don't like without erasing all the time. It also lets me refine areas that are working in the drawing. The cool bonus is that it gives you a little bit of value to work with to make it pop. If you scan it into photoshop, the graphite and paper grain from all the rubbing give you a little bit of texture within the file to adjust the color and value for a little extra fun, or fix if the drawing needs some help. Give it a try and tell me what you think. Thanks for the watch!