Not sure what others do in this situation, I have given a choice of 3.
- A dedication (free choice of poem to me although I guess the commissioner will have some preference).
- Time in residence plus a poem
- Free choice of poem subject to commissioner
Now I am left wandering what they will choose in a 16th century kind of way...and delighted to see that the web is full of people offering their services on this basis in the 21st too.