Our trip to Sydney was initially a holiday of a lifetime, which we had booked a long time in advance. After booking the holiday we decided that we would like to get married while we were there. To get married in Australia, you need to contact a celebrant (Pauline Faulkner) and fill in an "Intention of Marriage" form (received by e-mail) which needs to be signed by a solicitor. A copy needs to be faxed to the celebrant to start the ball rolling.
We decided that the Royal Botanical Gardens would be our location, so we let Pauline book the venue, transport, photographer, and witnesses (two were required, one being the photographer). I hired a suit in the UK, which I took in my suitcase, and my fiance bought her wedding dress, which was packed separately. I contacted the air lines (BA and Qantas) to ensure there would be no problem (or charge) for carrying the extra hand luggage (which there wasn't).
The wedding day arrived, I went to fetch the bouquet from a nearby florist (arranged when we got to Sydney), my fiance had her hair done, and we waited for our wedding car. The car arrived on time, and we were taken to our wedding venue. The ceremony took place in the Royal Botanical Gardens with Sydney Harbour in the background. The ceremony passed without a hiccup, and we were soon man and wife. You need to show your birth certificates and any divorce papers to the celebrant to complete the paperwork. A presentation marriage certificate is provided on the day, and the official certificate is sent by post some weeks later. The photographer took loads of photos before and during the ceremony. The post-ceremony photos were taken at various vantage points as we made our way to the Sydney Opera House.
If you are thinking of getting married in Sydney, I would highly recommend it; having both been married before, it was a lot less stressful than the first time, if not a little selfish, as we did not tell a soul we were getting married.