Thank you for considering me as one of your references. 

As much as I would like to help, please understand that I can only write an effective recommendation letter iff you have worked with me directly, e.g. completed a thesis or a project that has led to peer-reviewed publication, patent, funding, or award. Me being your academic advisor, or getting a good grade in my course or course project is not enough to write an effective letter since this is reflected in your transcript anyway. Therefore, please pick proper letter writers who know you well enough to comfortably write a meaningful letter.

Now, if you would like me to write a letter for you, then please send me a polite email with the following items:

1. Remind me of your student ID and any major types of interactions we have had (e.g. courses, GA/TA, project, research, grant, etc.) and the timelines.
2. Give me a list of points with brief details that you would like me to include in the letter and remind me of incidents where you have demonstrated some of these traits. 
3. Include a link to the job posting or the program details, and passionately tell me why you want whatever it is to which you are applying.
4. Your CV.

& btw, I would need at least a week's notice! Thanks for understanding.

Good luck!