On Assuming A Character

People have many different approaches in acting, when it comes to taking on a character. Some will look at how other people have done it; some try and remove themselves completely from their own personality; others use past experience to help a develop a character.
While each of these, I believe, may and can be helpful to different people and in particular situations, I am of the opinion that an alternative approach will, in the majority, produce a better result.

The methodology I take is this: look at the character, and their personality, their lifestyle, thoughts and emotions. Then look at your own. And find the common ground. A link. In some situations, it may perhaps be tenuous; in these cases, perhaps you need to look further into yourself or the character - or in fact aren't particularly suited to the character that you are attempting to assume. However, in the vast majority of cases, I believe that a reasonable link can be found, possibly several.
These links can then, in turn, be used to assume the character. If, for example, the link is that both you and the character are proud and strong; emphasise that, pronounce that aspect of your personality more significantly, while downplaying aspects of your personality that are more contrary to the character being assumed.
A point; if this link, though it be part of the character, is not the most significant - or, possibly even quite subtle - do not over-pronounce this aspect. (Unless it is a farce; but these tend to follow some of their own rules.) There is, of course, some creative licence given; but do not be too liberal in your interpretation, or you can miss some of the subtle reasoning in the writing and interplay between characters.

How your character relates to the other characters is just as important as the character's personality; and, of course, is directly affected by it. As such, make sure you first establish your link to the character before looking at how they relate to the other characters.
Your chief reference here is the script. In here are all your interactions with other characters. Go through and look at how you interact with each one separately; just as you interact with people differently, so does your character. Your character's relationships with other characters are just as varied, multi-layered and intricate as your own.
Another important point here: good relations with the other actors are crucial for good relations onstage. Even if your character is the most stuck-up person that hates everyone, that doesn't mean you should be like that backstage. Establish a good relationship with all the actors; know all their names, if you can, though this may be difficult for larger musicals. But if you have a bad relationship backstage, it will show onstage; and not in a good way, even if you're supposed to be angry at each other.

The final important point is to develop the character. Your idea of them at the beginning will likely change to the time of your first performance; and may well change during these performances. The reaction of an audience to what you do can sometimes be surprising; you may not find something funny, because you see and hear it every week - but they may find it hilarious. This doesn't mean that you should change things to elicit further response; you don't want to throw other actors off, either.
Changes to your character are a normal and necessary part of assuming the character. Without any development, your character may well lack subtleties or finer nuances which can be the difference between a good performance and a great one. Development may come from the director, other cast members, further analysis of the script, self-reflection, the presence of an audience, or simply time. Any and all of these are valid and significant ways of developing your character; don't babysit it! Don't be afraid of suggestions by other of changes!

In summation: upon assuming a character, first, establish a common link between you and the character, and use that to drive your portrayal of that character; second, establish the interactions and interplay the character has with other characters, to a realistic level; thirdly, develop your character through feedback, analysis and introspection over the course of rehearsals and performances.

Above all, remember two things: your character is never completely removed from you, and never can be; but neither is your character completely you, and as such wholly indicative of your personality. They both influence the other, but are still different. You are not your character, and your character is not you. Each of you has a bit in the other - hence the link - but are still partially separate.

And enjoy it, most of all. That's what it's about, after all :)