Choose items you can mix and match for different situations. For example, you can wear the same cardigan over a dress for a night out or with jeans for a day of shopping. Think in terms of layering. Pack lightweight items that can fit easily over one another depending on the weather. Pack items in the same color palette, like warm browns or black and white, so every item you pack matches every other item.
Bring comfortable shoes that can be dressed up or down. Shoes are often the bulkiest item in a suitcase, so bring as few pairs as you can get away with. Unless you're going to a formal event, some decent black or brown sneakers work for men, as do ballet flats or nice sandals for women.
Use every bit of available space. Stuff smaller items into shoes, and use socks to pad fragile items like electronics. Fold clothing neatly to minimize the space it takes up.
Minimize your grooming routine. If you don't want to use the shampoo and conditioner provided at the hotel, pick up a bottle of two-in-one shampoo and conditioner. If you wear makeup, leave all but the most essential cosmetics at home.
