Illustrators in this area of work often work to their own standards. Many illustrators work digitally e.g. Haley Newsome uses Photoshop and Andrew Hussie uses Microsoft Paint. Because they work for themselves their work is limited by their own choices so they have a lot of freedom to work how they want.
Many comic artists are inspired by other media. Many take inspiration from other comics or manga as well as TV and even their own experiences. Being able to work quickly to a deadline is important in order to be able to post consistently to a schedule.