There are different ways actors approach their method. During the filming of Lincoln we heard stories of Daniel Day Lewis taking method acting to new levels. There were of course ridiculous claims made about Jared Leto on the set of Suicide Squad. Actors utilize different approaches to their work, and have personal routes to crafting their performances. During an interview with EW Mark Hamill discussed his technique while working on the upcoming film, The Last Jedi:
“Actors like backstories. They want to know motivation and all those things, and it’s such a blank slate”
Concerning his character, Luke Skywalker, he elaborated:
“You know, if you look at it intellectually, I realized that it’s not my story anymore and so what did or did not do in the intervening years aren’t really important to the audience at this point, but I have to work it out for myself.”
The actual backstory that Hamill made for his character is quite dark. It appears that Hamill wanted his character to have a troubled past, although not one that corresponded with what we have seen in Star Wars canon:
“He left the Jedi to raise this young child and marry this woman. And the child got hold of a lightsaber and accidentally killed himself.”
Hamill then talked about Rian Johnson, and specifically how he and the director worked together to help paint the emotional backdrop for Luke.
“He was really nurturing in that regard, encouraging me to find ways to justify the actions in this movie. But like I say, that little story I told about Luke leaving the Jedi and getting married, that’s not officially what happens.”