OK, so my firm celebrates administrative assistants week in lieu of administrative assistants day. Well, the lawyers have been charged with writing a poem for their assistant. I am not creative at all...I need your help GRB!
So--what is your assistant like? What does he/she take pride in? If you were to praise performance, what would you single out? Does the person want to be considered a friend? A professional? Level-headed? Sane?
You could think of doing an acrostic, in which the first letters spell out a word, such as Thank you.
And you could use adjectives to describe the person, with a short sentence in the final line or two. That's only eight lines, so not too hard to do.
A heart-felt prose poem would work. You can even create a found poem based on two or three sentences of well-written material.
You can also write a parody, but you'd have to choose wisely, I'd think. Keep things short, line up three or four words or images that you want to use, and you could put something together pretty quickly. A quatrain (four lines) might be just enough.