Gather information about your teacher. A brief resume would do. Collect letters of recommendations from your other teachers to validate your choice. With this and other material proof of your choice, begin your task.
Address the letter to the person or persons who will ultimately make the decision. Start with a salutation and a formal but friendly address. Introduce yourself and the purpose of your letter. This information should be condensed into one opening paragraph.
In the second paragraph, introduce your teacher. Give the basic details first, such as name, location, a brief job description. Remember that you will be attaching a resume with your letter, so there is no need to go into excessive detail here. Just give a brief introduction, and then clearly state why you believe your teacher is the best nominee for this award.
In the third paragraph, describe how the teacher has affected you. This should be the most detailed part of your letter, where you should make a personal appeal and add experiences that make the teacher stand out as unique and extraordinary.
Conclude the letter by thanking the person or persons you are addressing for their time and sign off. Do not forget to give your own details (name, address, telephone number, school, grade) at the end of your letter. These are important references that the award committee will require.