There are a lot of things that can inspire someone when it comes to how they are going to "play a role." Costumes are usually super inspiring to me, especially the shoes. When you wear different types of shoes (boots, gym shoes, dress shoes, flip flops, etc.) you naturally carry yourself differently in each pair which in turn, would make you play the role slightly differently in each shoe.
"I'll bet those are comfortable shoes."
Another inspiring character choice can be an accent or dialect. Someone from the southern part of the United States is going to naturally have a different vibe than someone from the UK. Someone from Russia will have a different vibe than someone from Ireland. Make sense?
Another choice is haircut. This is a big one for me. How the hair is styled and cut makes a very big impact on how I go about playing a role. If the hair isn't right, I have a hard time really "feeling it" when it comes time to jump on stage. In Part of the Plan, I get to have a James Dean type haircut which I really like because I feel like that style fits me personally and the character well.
One thing that is really inspiring to me are photos. When I get cast in a role one of the first things I do after I read the script is look for photos I think relate to the character and the characters "essence." The photos can be of anything. A sunset, a bicycle, an animal, the inside of a coffee shop... anything as long as I think it relates to the character in some way.
Below is a collage or "vision board" of photos I've collected throughout the past few weeks that I think best represents my characters thoughts, feeling, emotions, sense of humor, sense of reality, interests, family, life style, etc. If you're an actor (or any creator for that matter) and are ever stuck on where to go next, or how to get a little deeper into a character, maybe a character vision board will give you some inspiration and help you move past some of those road blocks. Here's how I've put together mine for Sean O'Connor in Part of the Plan.