Blue sky thinking is one of those hideous marketing terms that means just come up with loads of ideas no matter how crap or stupid they are, but you can apply the concept to cartooning as a way of getting out of a rut and generating some new designs.
A fun exercise is to take a photo of a famous actor or pop star or just anyone who has an interesting face and just base a character on them. Here are some I did this week. Can you work out who these are based on? As Stan Lee used to say, a "no-prize" goes to the person with the first correct answer. BTW The clue's in the file name.