As I had not yet photographed/videoed Oli playing guitar I took some Kings of Leon photos off the web to try the tracing idea. I think this works quite well.
I also had a video of Isaac on his bike so I converted this to Jpegs and traced these. The images I traced were black and white. I think they would probably be easier to trace in colour as there would be more definition.
I like the idea that they run in series which is approrpriate to this action (ie going forwards in a line)