eBay Australia has been promising and then delaying plans to make all sellers include a returns policy and detailed shipping information when they list items for much of this year, but it's now definitely happening. From September 15, all listings will need to specify a returns policy, how the goods will be delivered and how much handling time will be expected.
That sounds like a lot of work if you just want to clear a few unwanted items from around the home, though there are a few steps you can take to simplify the process. For instance, you can simply state that there is no returns policy as such. (That won't get you out of basic consumer law obligations to describe goods accurately, but it will make it clear that you're not operating as a commercial entity.)
Ensuring that there's a clear procedure in place to handle returns and clear shipping and handling information isn't a bad thing for consumers, of course, but it's also yet another reminder that these days eBay is much more about new goods than selling unwanted items and also much more about fixed-price listings than auctions.