Boxing Day sales are the biggest deal event you can find after Christmas. However, there is still something going on with the catalogues of Big W, Kmart, Target and other stores. You can always check out this page the day after Christmas to see any clearance sales. Most of them are either stocktake sales or Boxing Day sale catalogues.
There are also New Year sale catalogues in which you can find party snacks and decorating items.
Games, toys, entertainment products, home appliances, clothing, and more products might be subject to the catalogues of Boxing Day.