If I've directed you to this page, it is because I want to give you some advice in how you request a letter of recommendation from me.
My advice is adapted Dr. Shanafelt's blog, whose full and original post you should read first: https://www.carrieshanafelt.com/asking-for-a-letter-of-recommendation/
Again, read the above post. Do not treat letters of recommendations like a chore or a box to be ticked; they are an opportunity that you should use in your favor. Reflect on what you think I could reasonably say about you, and how it could be strategically helpful to you.
In particular, if your only real relationship with me is that I'm your major advisor, then I am not in the position to write for you what I consider a 'strong recommendation' --- as your advisor, I advise you to reflect harder and ask someone whose perspective on your work would take better advantage of the opportunity afforded by a letter of recommendation.
If you feel prepared to write me a request, begin your draft e-mail, making sure to follow that advice while also covering these points:
- You. Remind me when you took my class and what class it was, or otherwise in what capacity you've worked with me.
- Context. Explain the program or position you are applying to and why it is important to you in terms of your life's goals. Let me know why this opportunity and/or your goals are important to you, to your family, or to your community. Be sincere. (If I think I'm an appropriate person to write a recommendation for you, I may use this context when I talk about you.)
- Why me. Explain why this recommendation should come from me, rather than another professor in whose class you did well.
For example, how is the course you took with me relevant? How are the skills you demonstrated in my class relevant? How are the projects you did in my class relevant? If you are using multiple recommendations, explain who else you are asking and how my recommendation would fit into that portfolio of recommendations.
- Logistics. Give me all the logistics up front: (i) when is it due, (ii) how do I submit the completed letter, and (iii) to whom is it going?
Give me a month's notice if possible. If you are running behind, be clear and apologetic.
Give me everything I would need to write a professional letter: if it goes to a person, I need their full name and title/position; if it gets mailed, I need the address.
- Attachments. Attach your resume/CV. Attach any draft materials you are submiting. Give me a link to any online information abount the opportunity you are pursuing. Tell me what each link and attachment is. If you don't have these things immediately, promise me up front what you can give me and when you will give it.
Before you hit send: proofread and spellcheck; read your email aloud; make sure your opening and closing are professional and express gratititude; double-check it is going to my SSU email address; give the email a a good subject line (like "Request for recommendation for [purpose]") then hit send.
For the record, it is unprofessional to ask me for a copy of the recommendation after I have submitted it. You may be curious, but unless I make the offer to send you a copy, do not ask.