Tips for asking for letter from current employer?

[shrimps]

Hey GradCafe Team,

I'm applying for MPA/MPPs this fall. These are all professional programs, so I'd like to have a letter of rec from my current supervisor who I get along with very well and work closely with day-to-day. However, because this is a LOR request plus "oh, by the way I'm applying to grad school" email, I've been putting it off like crazy.

Since most of us will be asking current supervisors for letters of rec, does anyone have any example emails or general tips for how to do so classily?

Many thanks!