Music - what music will be played as you enter and as you leave? Do you want to play music as you sign the Marriage Licence? You may even want someone to sing?
Entrance - who is going to escort the bride?
Vows - are you going to write your own or are you going to use some that are already available?
Rings - will you both have rings and who will be the ring bearer?
Signing - don't forget you need to arrange a table or similar for the signing. Who will be your witnesses?
Themes / extras - do you want to incorporate a Sand Ceremony, a Wine Ceremony, Marriage Rocks, Keys to a Successful Marriage or something else of your choice?
Your Celebrant should be available to discuss all this with you and support you with your choices. It can be a good idea to contact several Celebrants and then work with the one you feel most comfortable with - you do have a choice!!