If you know ahead of that time that you are going quit over the phone or resign via email be sure you haven't left any personal belonging at work. It's awkward to have to go back after you've quit, so take everything you want to save with you. Also, don't leave any personal information on your work computer.
How To Quit A Job Over The Phone
Talk to Your Supervisor. The best way to quit a job over the phone is to call your supervisor and explain why you are quitting. Don't say much more than you are leaving, but if you have a reason for quitting that sounds legitimate, use it. For example, personal or family illness are reasons why you could have to quit without notice.
Leave a Message. It's not the bravest way to quit a job, but if you feel uncomfortable talking to your boss, you could call after hours and leave a voice mail message. Again, it's not going to win you a good reference or probably any reference, but if circumstances are difficult at work, you may not get a recommendation anyway.
In both cases, if you're not going back to work it's important to apologize for quitting without notice. Say that you regret, due to circumstances beyond your control, that you need to resign immediately.
Let the company know what to do with your final paycheck if you don't have direct deposit i.e. ask them to mail it to you. If you have personal items that you need to get from work, ask if they can be packed up for you and make arrangements to collect them.
Resignation Articles and Advice