As with so many skills this one sounds incredibly obvious and incredibly easy.  As with so many skills it isn't.  Picking up an Aussie Rules ball, especially when it is moving, is difficult at the best of times, but when you also have to get it first times, whilst running and contesting with opponents it can seem impossible.  However, by rehearsing a few simple techniques you can greatly improve your chances of succeeding.

Practice first with a stationary ball.  Walk up to it, put one foot next to the ball and bend at the knees and waist.  This will result in your head going down, so try to be aware of opponents around you who may be charging in and brace yourself for any bumps you might receive.  Place both hands on the ball, scooping it up with one into the other.  Avoid picking it up with one hand if at all possible - this is far more likely to go wrong.

Once you are comfortable doing this at a walk increase your speed gradually, varying your sides and approach.  You can then move to doing the drill with a moving ball, although this is obviously much harder.  As the ball is not round it will bounce all over the place, so be sure to keep your eyes firmly on it at all times.  Aim to keep your elbows together and behind the ball, so that should you not manage to grab the ball you will at least knock it forwards, keeping it in front of you and giving you another opportunity to put your hands on it.