What sort of letter you choose to write to your ex-boss depends entirely on what sort of job opportunity you are chasing. If you are seeking employment at the same company again, then you will need to remind your ex-boss of the outstanding qualities that you demonstrated last time you worked for them and why you would be an asset to the company if you were to return again.
However, if you are seeking a letter of recommendation in order to help get you employment somewhere else, then you will need to write a polite letter to your ex-boss explaining exactly what the new job is and what you would like them to write in the letter.
If you are writing a letter to seek a job opportunity with your ex-boss again, then you might want to set out a letter like this:
Dear Mr/Mrs Smith,
I am writing to you to ask about any potential vacancies and job opportunities that might be available at your company at present or in the near future. I am currently seeking new employment and I would be incredibly enthusiastic about working at [name of the company] again as I enjoyed my time there in the past a great deal.
As I hope you can remember, I have a very strong work ethic and maintain the utmost standards of professionalism in all of my work. My list of achievements when I last worked at the company included [details of achievements].
Since leaving your employment last I have worked as [detail your other jobs here] and I believe these experiences have enhanced my abilities considerably.
I would be grateful for any opportunities you might be able to offer.
Yours sincerely,
[Your name]
However, if you are seeking a letter of recommendation in order to help get you employment somewhere else, then you will need to write a polite letter to your ex-boss explaining exactly what the new job is and what you would like them to write in the letter.
If you are writing a letter to seek a job opportunity with your ex-boss again, then you might want to set out a letter like this:
Dear Mr/Mrs Smith,
I am writing to you to ask about any potential vacancies and job opportunities that might be available at your company at present or in the near future. I am currently seeking new employment and I would be incredibly enthusiastic about working at [name of the company] again as I enjoyed my time there in the past a great deal.
As I hope you can remember, I have a very strong work ethic and maintain the utmost standards of professionalism in all of my work. My list of achievements when I last worked at the company included [details of achievements].
Since leaving your employment last I have worked as [detail your other jobs here] and I believe these experiences have enhanced my abilities considerably.
I would be grateful for any opportunities you might be able to offer.
Yours sincerely,
[Your name]