When I was a wee girl doing GCSE art, we had to buy a set of these amazing colour pencil crayons. They only cost £12 a box of about twenty(ish), and they were so good, they lasted me even to this day.
Then Berol discontinued them, and I was very unhappy.
Derwent just doesn't seem to do as well as Karisma. Haven't found any pencils as good, anyone have a brand they swear by?
Also, read this a little while ago. It's an interview with a comic book artist, Mike Maihack. It's a bit geeky, but geeky is good. http://flickeringmyth.blogspot.com/2011/09/sketchy-details-conversation-with.html