Sample request for recommendation letter

Professor Smith,
As you might remember, after graduating, I moved to Far Away Land, where I have been working as a [Position] at [Organization]. Well, I’ve recently decided to take the plunge and apply to graduate school! The program(s) I am looking at compliment both my undergraduate work and things I have learned and done since then.
Your recommendation was vital in my getting my current position, and I was hoping you would be willing to do the favor once again. The deadline is a month away. Let me know what you think, and I’ll send you all the details.