The substance of the letter should be divided into three parts as follows: -First paragraph: Briefly introduce yourself and the reason for writing the letter. Second paragraph: It should go into great depth on the subject. Third paragraph: In this paragraph, you must end your letter by providing the conclusion or solution. You can use these templates as a guide. In addition to the above points, here are some other tips to keep in mind while writing a formal letter: -Do not write on both sides of a paper document-Use black ink only-Do not sign your name at the end of the letter. Formal letters are used in business communications and require strict adherence to grammar and etiquette. A formal letter must be written with correct spelling and punctuation. It should also be written in an appropriate tone. The writer should identify themselves at the beginning of the letter and conclude with "Sincere regards," or some similar phrase. Formal letters can be mailed through the postal system or delivered in person. If you send a formal letter via mail, it should have enough space to fit all the information required. Businesses may have specific requirements for writing formal letters. For example, they may want you to include your address, telephone number, and email id at the beginning of the letter. Also, each section of a formal letter needs to be given a specific title.