Use the extra time to your advantage. There are plenty of things that you can study prior to OSB. I'm going to be spending a lot of time on leadership and the theories behind it. If everyone is a good pilot, the interview at the end of the process could be the thing that sets you apart from everyone else. Afterall, when you're in the RAAF as a pilot you're an Officer first and a pilot second.
Another idea could be to get some extra flying in. It doesn't necessarily have to be you flying the plane either. Back seat time in a small aircraft is fantastic to get your head around all sorts of things. This way you will be able to see the bad habits that people get in with their flying and if you already have some flying experience you might find a few techniques to areas that need improvement. I'd suggest finding a flying school or aero-club that has a CPL course attached to it. When I was doing my CPL my instructor encouraged me to take people along because it gave me the chance to practice commercial operations with passengers. So this way you can scratch their back and they can scratch yours. Both you and the student will get something more out of each flight.