Explain why you're leaving. Briefly explain the reasons you've decided to leave, both related to your current job and to your new position.A good resignation letter is a simple one. There is no real need to elaborate farther than you have to. You don't even need to give a reason. You can simply write, "Please accept this letter as my resignation. Here's how to write a resignation letter when you're quitting for a job with a better compensation package, and you want to provide your employer with a reason. Please accept this message as my formal notice of resignation. I am fortunate to have received a long awaited opportunity that I cannot pass up. Professional resignation letter examples for different reasons.