Dear _____ [student whose name I don’t even know],
I hope you _____ [are doing well/know I don’t really care about how you’re doing]. I have received your request asking for a letter of recommendation for _____ [medical school/Goldman Sachs/moving back in with your parents]. They would be ______ [lucky/screwed] to have a such a _____ [hard-working/lazy/over-privileged] student like you. It is great that you are planning your summer so _____ [far in advance/last minute]. I am well aware that you ______ [are passionate about this field/have never opened my textbook/only got into this school because the library is named after your grandfather].
However, I am currently very busy _____ [writing a book/running for president/taking Buzzfeed quizzes]. Since _____ [I am so busy/I simply do not want to/you slept through every lecture], I unfortunately must decline to write a letter for you. Perhaps, if _____ [you had given me more notice/you ever handed in a problem set on time/I actually knew who you were], or if you hadn’t _____ [given me such a bad Q score/used my class to Facebook stalk the guy you hooked up with last weekend], I might have been able to help you. That said, I _____ [am certain/highly doubt] you will find someone to write you an excellent letter. I wish you the best of luck _____[finding someone bored enough to actually write you a letter/convincing your future employer you didn’t lie on your resume/moving back in with your parents].
Best of luck, _____[what’s your name again?]