I have the benefit of knowing a lot of people that I've stayed in connection with since my first year of uni, and recognising that networking is an important step in hearing about these sorts of things, and so it's fairly common for me to learn of an opportunity and pass it on to someone else. To that end, it's just a matter of finding one or a few people who are in a similar position and being pleasant. I realise that's not exactly helpful advice for you, but if you do know someone like that, let them know that you're on the lookout and to give you a call if they hear anything.

However, another mistake that the people around me make is starting with the wrong question - "Who will give me a job?" instead of "What am I interested in?". Small firms that take on graduates are almost always specialist firms, and a hefty chunk of them have an idea of who they will hire before they even have a job available. Find firms that practice in the area you're interested in, and go directly to them. If they have a dedicated HR department, give them a call, they won't mind speaking with you about opportunities and it's okay to call back later. If they don't have a HR department, save your phone call for when you think they'll actually have a job for you, but also check back frequently.

The USyd job board is pretty good for picking out positions as long as you can demonstrate a genuine interest, but CoL, beyond law, gradrecruit and gradconnection (and Lode) are all less useful than Seek in my opinion.

But as I said, the real method of looking for a job in law isn't by literally looking, like you are at the moment. Looking for a job starts with finding individuals who are offering jobs and being on the radar. That is what I'm talking about when I say that students don't know how to search for legal jobs. I'm not someone who will say "It's all about who you know, not what you know", but it is fundamentally important to make yourself known to be someone that is proactive in their job search, and making yourself known prior to an opportunity being available is achieving that goal.