I always travel with just a carry-on because I hate hauling luggage around. I limit shoes, sweaters, and bottoms because these tend to be space hogs.
For a warm/cool capsule, I'd probably wear dark wash jeans (jeans let me sit without worrying about grubby benches) for the cool temperatures and pack a light-weight skirt for a warmer climate and/or dressier occasions. Then I'd throw in a pair of lightweight dark pants that could work for both climates and dressier events along with a pair of shorts for casual, hot weather wear. Occasionally, if I have room, I pack a pair of lightweight nylon sports pants that I could wear in rainy weather and when the other bottoms are getting laundered.
I like light-weight T's since I can pack a stack of them in my packing cube so I can wear a clean top every day. Shirts take up too much room and the collars get wonky in tight quarters. I can layer the T's as needed and, because they are light-weight, they dry very quickly. I take two sets of undies--one on my bod and the second in my bag--and give them a quick swish in the sink every night when I'm washing up; they dry by morning so I always have clean undies in my suitcase. If I think I need more warmth, I'll throw in my silk undershirt and long johns. I sleep in an oversized T-shirt.
One sweater (usually a cardigan because it serves as both a jacket substitute and buttoned-up as a pullover), a light-weight windbreaker, and my lightweight travel trench are my outerwear. I sometimes wear one, or more of these, on the plane--or, depending on what I will be doing, wear a zipped or blazer style jacket.
Shoes take up a lot of room so I try to limit them to not more than two pairs in my bag. Flipflops are good for hotel rooms as well as beach wear.
Packing Tips: Pare down on cosmetics and lotions. Pack a small bottle of detergent for washing stuff out in the sink. Use packing cubes and Ziplock bags to corral everything, To save space, put bulky items like your sweater, trench, and windbreaker in their own individual large-size Ziplock bag, sit on the bag to squash out the extra air, and then seal the bag. You reduce the size by 2/3 and these items will be easy to find when you need them. Buy a couple of Eagle Creek packing cubes and use them to compress things like bottoms and tops. Roll things whenever possible. Stuff socks and anything you want protected into your packed shoes.
Whew--I could go on, but the best advice is to look at everything that you think you need and then reduce it by 1/3. And compress things as much as possible to save space. And remember, if you REALLY need something, you can probably buy it when you are there.