4. Have a deadline
Reach out to the recipient AT LEAST two weeks before you need it. DO NOT ASK FOR A LETTER THE DAY BEFORE YOU NEED IT!!! Be respectful of their time. In your email/letter, make sure you include the date you need the recommendation. I would also send a reminder email a couple of days before it's needed, if you haven't received it yet.
5. Include your academic resume so that they know your accomplishments