One day you might be asked to give a recommendation for someone that doesn't
really deserve it. If you can't say something nice, say something ambiguous:
To describe a person who is totally inept:
"I most enthusiastically recommend this candidate with no qualifications
whatsoever."
To describe an ex-employee who had problems getting
along with fellow workers:
"I am pleased to say that this candidate is a former colleague
of mine."
To describe a candidate who is so unproductive that
the job would be better left unfilled:
"I can assure you that no person would be better for the job."
To describe a job applicant who is not worth further
consideration:
"I would urge you to waste no time in making this candidate an
offer of employment."
To describe a person with lackluster credentials:
"All in all, I cannot say enough good things about this candidate
or recommend him too highly."