Write a salutation to begin the letter. If you know the person well, use his first name. If you are writing to an entire family, use the family name. Begin the letter with "Dear" to make it traditional and classy.

Include information on the reason you are writing the letter. Be sincere in your feelings on the matter and do not try to avoid the subject. People often avoid subjects that are too serious, but this can actually make the person feel worse. Be honest and upfront in the beginning of the message. For example, "I felt horrible to hear the news about your father today."

Write a line or two that personalizes the message. This includes things about the person who passed away or things that you are willing to do to help the situation. For example, "Please do not hesitate to call anytime if you need to talk. I am here for you" or "Your father was such as wonderful person. I remember his great laugh and dedication to you when we were kids." Keep this portion honest and personal in order to convey your feelings on the subject.

Finish the message by including a heartfelt statement. For example, "Your family is in my thoughts and prayers right now" or "I am sending you positive energy and love." Sign the message and deliver it to the individual in person or through postal mail.