Please note the following points if you are seeking a reference from me:
I may not agree to provide a reference.
Consider whether you may receive a better reference from another referee. It may help if you've engaged with me outside of class (e.g., in office hours) or asked me questions.
You must ask me at least one week before you pass my name to an employer as a referee.
In your email identify all positions you are applying for and when, so that I can estimate when references are due. Provide me with a summary of your grades so far as well as your start and end date at the university. I may ask you for extra details in reply.
Send an update request if you decide to make extra applications. My acceptance is not a blank cheque: don't assume I will provide you with references on an ongoing basis because I've accepted once.
If I receive any reference request from an employer and you haven't made me aware of this, I will reject the request.
If you've followed the above rules and are waiting on a reference from me, please do feel free to send me reminders. I will consider these a courtesy and not a problem.