Run the process and choreograph it so that the interested parties are progressing roughly at the same rate.
It can be especially frightening for people who were trained in strict dance techniques but never asked to choreograph for either themselves or other people.
Time Pressure - How much time do you have before the performance, not just to choreograph but also to teach your dancers the routine?
Prague This time last year I went to Prague to choreograph a solo on a very pregnant Daria Klimentova.
While in New York later working as a teacher, she began to seriously choreograph her own pieces, further breaking out of the box.