1. Wear Your Bulkiest ItemsIf you need a jacket or blazer on your journey, save space in your luggage by wearing or carrying these bulkier items. Toting more than one pair of shoes? Always wear the heaviest pair on travel days.
2. Use Space-Saving BagsSeparate your belongings by type into smaller plastic cases. You can squeeze or suction the air out of them to conserve space, and it's a great way to easily find your belongings as you unpack. Ziploc bags, which can also be re-used, work just as well in a pinch.
3. Make Use of Every Available SpaceFrom the oft-overlooked outer pockets to the space at the bottom of your case beside the handle tubing, there are lots of crevices in bags for tucking extra belongings. Use these smaller areas for things like socks, underwear, and other non-destructible items. Don't forget to stuff your shoes with small items (glasses, toiletries, non-liquid medicines), as well.
If your luggage has an expandability feature, consider using it only if doing so won't bump your luggage out of the carry-on-size category; the last thing you want to do after packing your bag this carefully is to have to check it!