While the prospect of spending two nights in the middle of nowhere, with nothing but a flimsy bit of plastic to protect you from the elements, may not appeal to everyone, the ONLY way to do Fraser is to camp. There are a number of campsites around the island, but most have a 9pm quiet time policy, so most backpackers head to the beach.
Before you leave for the island, you will be warned of the dingos and, believe me, you will see them. The faintest smell of cooking and they will be round your campsite like a shot, whether you notice them or not! One popular place to camp is Indian Head and getting up at 4am to catch the sunrise is amazing.