Experiment with Subject and Composition
It's relatively easy to get out to a park or garden where the leaves are turning orange and red and snap a few pics. It's more difficult to make an image that means something. Taking a bog-standard landscape should therefore be avoided.
Think about the composition of your image and what you may wish to include. Instead of setting the camera to 28mm and releasing the shutter, change your lenses around. Use a macro lens or your camera's macro function to focus on the close up details of autumn. As red-orange leaves turn to brown and break apart on the often wet ground, miniature details make all the better photos than yet another nice albeit same-same landscape of trees and coloured leaves.
Like with general photography, your lens aperture can be used to isolate or enhance your photographic subject. Setting your camera to aperture priority and taking your image at f/1.8 or f/2 will allow plenty of light into your image and will isolate your foreground subject by blurring the background. This can be particularly effective when capturing hanging leaves.
A larger f-number (a smaller aperture hole) of f/8 or f/11 will allow you to get more of your shot in sharp focus. This would be best used for landscapes or similar shots where you wish to capture a wide scene.
Find the Light
While light is a necessary component of photography (literally painting with light), bright sunshine is not and in many cases should be avoided.
For most of autumn, Australians will have ample light, even after daylight savings ends. The morning and late-afternoon light can be particularly pleasing, providing a rim lighting on subjects such as trees and leaves. Shadows can also be interesting during these hours.
But overcast days can be particularly pleasing too. For starters, overcast days provide even diffused light all day, meaning the harsh middle-of-the-day sunlight is diminished. This makes it easy to make nice images all day long without worrying about the angle of the sun too much.
Also, take your camera with you wherever you go so when a one-off combination of light and autumnal subject happens, you're ready to snap it.