Find a laundry or dry-cleaner near your hotel. I travel throughout the world on business and pleasure. This is one of the easiest ways to keep the size of your luggage manageable and save money by avoiding the high cost of hotel cleaning services. Many laundries offer hourly or daily service and will return your clothes fresh and folded.
If flying out of an unfamiliar airport, arrive earlier than you think you should. My girlfriend and I flew from Austin, Texas, to Montego Bay, Jamaica, and arrived at the airport extra early just in case. Some event was happening that weekend, so the security line ended up taking about two hours to get through. We saw many people miss their flights that day.
Pack at least one fleece blanket (for the plane trip and maybe the hotel), and always take your own pillow.
Pack by rolling some clothes — but with a twist. To keep my shorts separate from my shirts, separate from my slacks, I stored the rolled garments in a single layer, side by side in an oversized plastic bag with a zipper-lock. Each bag usually held four to six pairs of whatever type clothing I separated. Before placing the bag in my luggage, I would slide the "zipper" to nearly closed, then squeeze out all the air, then zip the closure shut. This method gives you easily accessible, wrinkle-free clothing available any time without disturbing anything else. It's a space saver and an organizer.