to
set or stipulate one's own
conditions or to be able to
determine one's
course or actions freely or according to one's
individual needs or wishes.
Ticket here is used with the idea of something that gives or entitles one to some privilege or
service, such as getting into a show or traveling on a
plane. If one were able to write his own
ticket, he could stipulate the privilege or
service he should get, such as which show he wanted