To write a short notice resignation letter, include your position and effective date, explain your reason and express gratitude. Use their name and formal title, such as "Dear Mr. Smith" or "Dear Dr. Johnson.If you want to know how to write a simple resignation letter, here is a step-by-step guide with an example. Dear Dr. NAME: This letter is my official notification to you of my decision to resign from Wayne State University. Add contact details, company name, and date. Sample Resignation Letter. State your position on the day of resignation: Always mention the position you held in the office on your last working day.