My best advice is having a fellow Celebrant mentor or 2!
When I started out, I went to a couple of ceremonies of experienced celebrants and observed, when asked lots of questions at the post-ceremony debrief.
In most parts of a ceremony, there is no right or wrong way to do things.
Develop your personal style and market that!
It is also great to phone-a-friend when driving home from a ceremony, to share a fabulous or challenging moment with a Celebrant friend, knowing you are in a safe space to do so.
Mentors can be Celebrants you studied with, Celebrants local to you and/or Mentors that AMC may suggest for you!