Your movie, television series or play is nothing without a character sketch. I find the character sketch the most essential tool to writing a script. When I write something new, I don’t put any lines or action to a page, unless I have that character sketch first. I feel I cannot move forward without one, because nothing would make sense. It also helps me to keep track of my character. 
Imagine if George Lucas sat down and just started writing “Raiders of the Lost Arc” without knowing anything about Indiana Jones. He would have had nowhere to go. Even if he scratched Indiana Jones fear of snakes on a notebook somewhere, it was part of his character sketch.
The character sketch gives you an idea of who your character is and what his motivation is within the script. It’s a questionnaire you ask yourself of the character. The first few questions deal with what your character looks like, such as age, height, weight and where and when he was born. You learn about your character your character’s backstory. The back story doesn’t necessarily come in the form of one question, it can come in the form of three or four. For instance, I have a question on my character sketch about religious denomination. 
When I was putting together Drake Darrow’s character sketch, the religion question, became an interesting part of his back story. He grew up an orphan in a Catholic Boys school and remained Catholic until he worked for military intelligence. Once his experiment failed, his whole life changed. His powers needed to be harnessed. In a dream he meets a long lost Atlantean, who tells him he is the only one that can save the earth from mankind. The Atlantean directs him to go on a pilgrimage to the far east, where he will meet Tsu Li, Dojo Master who has lived many past lives. Under Tsu’s tutelage, Drake becomes a Buddhist. Buddhism becomes an essential part to mastering his telekinetic powers.
Another portion of Drake’s backstory was a question about whether he had been married or not. I answered the question by saying that Drake had been married to his mentor’s daughter and then I elaborate in the question about where and when the marriage went wrong. I even put together some interesting tidbits of how they met and what their first encounter was like.
Many years ago I was given a book for Christmas called “Successful Script Writing.” The character sketch was the most important part of the book. I have utilized it. I found that not all the questions are relevant and have removed some. I decided to add other questions that I felt I wanted to know. Here is an example of the questionnaire I work from.
1: Name:
2: Sex:
3: Age include year born.
4: Astrological sign
5: Physical Appearance:
6: How does the character’s Physical appearance reflect their personality?
7: Describe the Character’s childhood, in terms of where they grew up, how their background effected them, their lifestyle and childhood activities or hobbie.
8: Describe the character’s relationship to his parents.
A: Father
B: Mother.
9: Describer the character’s relationship to siblings.
10: Describe the character’s relationship to other key people in their youth.
11: Describe the character’s education, include anything higher education, or whether they finished school, dropped out, of grammar school, high school or college and any relevant military education.
12: Describe the character’s history after any schooling.
13: Describe the character’s current relationship to parents.
A: Father:
B: Mother.
14: Describe character’s current relationship to Siblings.
15: Describe the character’s current relationship to any key people, whether be growing up, or people that had an impact in their life after any education.
16: Describe the character’s romantic life.
17: Is the character married.
18: How does the character feel about Marriage if he is, if not married how does the character feel about the idea of marriage or relationships with significant others.
19: Describe the character’s sex life. How does the character feel about sex. Is the character passionate in bed and to what degree if they are.
20: Does the character have children?
21: If so, what is their relationship to their children.
22: If not how does the character feel about children.
23: What is the character’s religious background.
24: What is the character’s current religious belief.
25: Describe the character’s moral beliefs. Does the character’s actions reflect their moral beliefs. Does the character do what they believe is right or wrong due to certain circumstances. Does the character’s moral beliefs coincide with their religious beliefs.
26: What is the character’s occupation?
27: Describe the character’s relationship to their boss. Is the character their own boss.
28: Describe the character’s relationship to their co-workers.
29: How does the character feel about their job?
30: What are the character’s hobbies or non work activities.
31: Describe the character’s philosophy of life.
32: Describe the character’s political views.
33: Sum of the main aspects of the character’s personality.
34: Describe the character’s state of health.
35: Summarize the character’s relationship to other characters in the script.
36: What is the character’s goal in the script?
37: Why does the character want to achieve this goal?
38: Who or what is trying to stop the character from reaching their goal?
39: What strengths does this character have that will help them achieve this goal.
40: What weaknesses does the character have that will thwart them or hinder them?
41: Does the character have an accent or a dialect?
42: Does the character use slang or professional jargon?
Not all of these questions may suit what you need and you don’t even have to know the answer to every one of these questions. If I don’t know the answer to a question, I skip it and move on to the next. Chances are as I am working on the script, the answer comes to me soon enough and I answer it later on.
So my advice is to work on a character sketch of your own and discover who your character is before you write them. You’ll be fascinated as to what you learn about your character through a simple thing as the character sketch.
The Script is the thing 