We like the idea of our's being like the following posters- where the only image on it is of the main character, (to show the importance of them to the film) Examples include:
However a more busier looking poster might be good also, as this will give the audience a bit more of an insight into what the storyline is all about. Examples of previous films posters like this, include:
I came across this website while researching film posters and it is quite useful...
http://www.all-film-posters.com/