Address your letter's envelope by hand for both formal and informal letters of appreciation.
Address your letter's envelope by hand for both formal and informal letters of appreciation.

Letters of appreciation express your gratitude to another person for good work, charitable gestures, excellent service or kindness. Taking the time to thank people for their efforts and contributions --whether to your business, organization or to you personally -- is a good way to build relationships, demonstrate attentiveness and cultivate future collaborations. Letters of appreciation do not need to be long, but they do need to be sincere and specific. Before you start writing, makes notes about the impact the person has had on you or your work. Use these notes to craft a well-thought-out letter that will express your gratitude in both tone and content.

Locate the mailing address of the person or organization to receive your letter of appreciation. For a formal appreciation letter, place the mailing address below the date. Your mailing address comes after the recipient's address. Align both the recipient's and your address at the left margin of the paper. Informal letters, such as a letter to a friend or relative, can be handwritten and do not need to include the recipient's or your address on the stationery.

Begin with the proper salutation. Your letter should start with the name of the person to whom you want to express appreciation. Include a last name -- "Dear [Mr./Mrs./Ms.] Smith" -- if you are writing a formal letter to a business or organization. Try to avoid using generic salutations like "Dear Red Cross." Whenever possible, address a specific individual within the business or organization. This shows a willingness to do the necessary extra research to make certain your letter gets to the right person. On a formal letter where you have no contact name, you may simply use "Dear Sir/Madame." If you know the recipient personally you can use a first name, such as "Dear Jane" or "Dear Grandma."

Craft the text of the letter. Specifically state in the first sentence why you are sending a letter of appreciation. Keep the tone of your letter sincere. A few well-chosen words of appreciation say more than sentence after sentence of hyperbole. A good opening sentence would be, "I am writing to express my utmost gratitude for your generous donation to our annual fundraiser." Follow this sentence by describing one or two ways your organization will benefit from this donation. For an informal letter, follow an opening sentence with one or two examples of what the gift or gesture meant to you. Being specific in your examples adds a personal touch that will help your letter stand out.

Close with one of several closing phrases, such as "With appreciation" or "In gratitude." For a formal letter you can always use "Sincerely." An informal letter can close with "Love" or "Warm best wishes," depending on your relationship with the recipient. Always sign your letter personally, regardless of whether or not the letter is typed or handwritten.