You may have thought the grass is always greener and decided to leave your job, but at some point you may find that you had it a lot better where you were before. If that means applying for a job at a former employer, you have the advantage of being good enough to get hired the first time. Now you'll have to convince the employer that you are committed to sticking around for the long haul.
Contact a few of your former colleagues, or even your former supervisors, to ask them to put in a good word for you. The faces of the company may have changed and the hiring managers who were there the first time may no longer be on staff, so don't assume your resume will be recognized when it lands on a hiring manager's desk. When you get a hold of former colleagues, remind them of the job you did or strides you made on the job so they'll have something specific to share with the people in charge of hiring. Also ask those people if you can list them among your references, and whether they have any inside information that can help you get the job, such as who's in charge of hiring, what those people are like, the characteristics the managers like to see in new employees or the best way to format your resume.
Highlight your recent accomplishments in your resume. To make your application as compelling as possible, you'll want to show your former employer that you've learned something new, gained new skills or made some significant accomplishments since leaving the old job. In other words, the employer needs to know that you've made yourself into an even better candidate the second time around. Talk about a few of your biggest achievements underneath each job title -- or titles. Include an "Awards and Recognition" section on the resume, which can put special emphasis on what you've done since leaving the old job.
Compose a cover letter that discusses your previous employment with the company in question, and what you've learned since then. You can bet that the hiring managers are going to want to know why you left the first time, what you learned since leaving, and why you want to work with the company again. Don't be afraid to grovel a little, advises CBS News' MoneyWatch. Give the employer an honest, yet flattering, reason why your current situation is not working for you, and remind the employer that you're already familiar with the company and that you'll be able to get up to speed quickly if hired.
Check in with the highest-ranking former colleague or boss after you've applied for the job, to try to find out any inside information you can about the position. If you gotten asked in for an interview, let your contact know that you're headed for an interview soon and that you could use an extra nudge getting in.