How to write a resignation letter that's effective immediately? We've rounded up tips and examples for writing a resignation letter that'll help you maintain work relationships long after leaving a company.Formal Resignation Letter Sample. Start with the facts and be direct. Learn how to write an immediate resignation letter with our comprehensive guide, including tips, examples, and a customizable template. What It Takes to Write A Great Resignation Letter. Create the perfect resignation letter in 30 seconds with our free AI resignation letter generator. (For example, "I regret to inform you that I will be resigning from my position, effective immediately. It's helpful to provide some basic information at the start of the letter. Give a clear reason for leaving, but there is no need to overexplain.