When I used to travel to Australia I didn’t believe in dragging a big suitcase, after the first time. I looked for clothes that didn’t crease too much as well as those that could be washed and hung. I travelled to Australia many times, during their winter, Europe’s summer.
A few weeks ago I visited Barcelona for 5 days, only to réalise a couple of days before a Vueling flight only a small bag max. 40x20x30 cm was allowed on in the cabin free of charge, I hadn’t checked when buying the ticket, otherwise pay 80€ extra. However, in the small bag I took there was enough room for underwear, nightwear, three changes of clothing and odds and bobs. I washed clothing in the evening as was needed and I was surprised how well I managed but I don’t glam up in the evenings.
I have noticed my older friends who come to stay with me seem to bring too much in large suitcases, whereas, the younger ones bring a bag.
Look at where you are going to stay and what the weather estimation is, then lay out all the clothes on your bed accordingly, eliminating the unnecessary items when all is sorted.