Put yourself in the reader's position and write in a friendly and helpful manner. Don't represent your company as one that cannot make a mistake and must always be in the right. Try not to reply in the normal bland and defensive way of organizations—write a sincere and helpful letter.
Show you are interested in the reader's circumstances. If he or she has mentioned something personal in the letter, refer to it in your reply. This builds a bridge between you and the reader. Read the original letter carefully and see if there is something you can put in your letter to show your interest.
Putting your reader/audience first .....
For all writers the most important people are their readers. If you keep your readers in mind when you write, it will help you use the correct tone, appropriate language and include the right amount of detail.
What do readers look for? They look for relevant information, presented in a clear, easy-to-understand style. They don't want overloaded, background information they already know, business talk and jargon. Above all, they want to get the general idea of your message in one reading. They don't want to dig for the meaning through long sentences and a boring style. So if you always keep your readers in thought, you will have to change your style and content to meet their needs.....for more on writing effective business letter visit http://www.managementthatworks.com