Thanks for the replies guys! I might go grab me some half decent pencils tomorrow, I already have a sketch pad.
I had a quick doodle of M55 this afternoon (no more than 2mins) using the image of it in starry night 2004 (which looks nothing like actual telescope images that I have seen online). Its going to take some practice but it should be fun! Here is my first non-genuine effort using a crappy unknown unsharp pencil.
Image was inverted in Gimp.