Rock and roll
It's one thing to pack shorts and summer dresses, as they don't take up much space. But how do you fit your favorite jeans, sweaters, and jackets into a small carry-on suitcase? It's simple: roll, don't fold. This way, your stuff will take up less space. Short and pants are also less prone to wrinkling this way.
You can pack small loose articles of clothing into compression sacks, which not only frees up space but keeps you from digging through your whole suitcase every time you need a clean pair of socks!