How to write a letter of recommendation. Please go through all of them so you would understand how to write this letter of recommendation and It will help you follow the criteria. There is a sample letter of recommendation in it in order for your reference. See the side notes written to it. Key points: Word count: 300-350 words Follow ALL the attachments thoroughly and write the email accordingly Write everything using your own words. There is a huge penalty for plagiarism. Use formal tone and good writing skills so it looks professional.