The 4:3 aspect ratio was used in television due to the circular nature of CRT screen (and to be compatible with a lot of Hollywood production in that format). Early digital photography sensor tech and nomenclature were derived from the cameras used to record television video. Of course that is an interesting parallel since movie film gave rise to the 3:2 photographic format.

In my experience, it is not what you have, but what you don't have that increases your creativity. For example would anyone call the New York Yankees style of baseball "creative"? So to that end what is required: A budget - to put a limit on the money you throw at the project A deadline - to put a limit on the time you spend A critic - to put a limit on your imangination