I took a step back and looked at my interests, what I was really interested in at the time and chose to try and create characters for an existing world. I had a look at the already designed races and focused on the characters role and personality. I ended up doing about 5 characters based on the Mass Effect game series by BioWare and EA in my own, comfortable illustration style.
I quite enjoyed creating some of these characters, making their personalities. It might even be fun to attempt 3D modelling one or more of these characters in future.
After these and still looking to try out a few new things, I decided to try and create characters in a way I hadn't done before. A friend of mine is really interested in animals and anthropomorphised characters. It inspired me to give designing similar sort of characters a go.
At first, I tried creating anthropomorphised characters for my own themed world, looking at adventure games and movies. Pirates was a... common theme.