List the witness's information. Formats vary by court, but you typically need the witness's name, address, age -- or a statement she is over 18 -- and place of employment, if any. Include a summary of job duties, her field-related education and her title if the case is related to the employer or her work. Use one line for each item.
List the items being sworn to. Use a new paragraph for each fact. For example, if the statement is describing a car accident, make a list of the events the witness saw in chronological order and include the accident details she is going to testify about, such as the license plate and her estimation of the car's speed. Group facts by subject in a large statement if possible. Use subheadings to divide facts by subject. For example, if the witness is testifying about the various policies of a business, subheadings might include "Hiring," "Termination" and "Bonuses."
Insert a sentence at the end of the statement affirming the contents are true. For example, "I certify to the best of my knowledge and belief that all of the information on this statement is true" affirms that the statement represents the witness' version of events. Local laws might require specific wording on the will-say statement; check with the court handling the case or laws regarding witness statements to verify the necessary wording.
Compare the will-say statement to prior testimony of the witness, if any. Check for contradicting, incomplete or missed facts. Speak to the witness and revise as necessary. Have the witness look over the statement for inaccuracies.
Ask the witness to sign and date the statement after the sentence affirming its truth.
Have her signature notarized, if required by the court.