Have you ever been in a position where someone asks you for a reference to get a job and you find yourself in an awkward position? You dont want to lie, but you really cant tell the truth because it will hurt.
Robert Thornton, professor of economics at Lehigh University, once composed the ideal letter to fit the situation:
I am pleased to say that this candidate is a former colleague of mine. In my opinion you will be fortunate to get this person to work for you. I recommend him with no qualifications whatsoever.
No person would be better for the job. I urge you to waste no time in making this candidate an offer of employment. All in all, and without reservation, I cannot say enough good things about him, nor can I recommend him too highly.