As requested by Jimi, I'll add some sketches here. The first is a nice bright bit of eye candy, our northern showpiece globular M13. The night I sketched this, using my 18", the conditions were too poor for 'serious' deep sky observing and, wanting to do something, I decided to look at M13 and sketch it. I used pencil on white paper then inverted it in Photoshop.

m13_inverted.jpg