It's important to plan your outfits ahead of time. I find that skirts are the best for hot weather, because you can pair them with t-shirts for a day look and a silk top or blouse for nights — I always pack two or three. A pair of jean shorts that I can wear several times with each of my tops is also a must pack.
For daytime, a pair of neutral-colored sandals goes with everything, and a pair of comfortable tennis shoes is important for long tourist tours. For nighttime, a little cotton black dress or one of the skirts with a silky top works for a nice dinner out with family or friends. A pair of black or neutral stilettos should be enough to get you through a week-long trip.
But aside from regular outfits, you should get creative. My all-time favorite and what I bring the most of in every trip is a long scarf that I wear in every way possible: as a blanket/sweater on the air-conditioned plane, as a sarong for the beach, as a dress with heels at night, as a cover-up while visiting temples and churches that require coverage for entrance. I'm also into bodysuits. I love them and totally rely on them! They fit in the smallest corner of your carry-on, even in your purse or inside your shoes. I wear them with my jeans and a necklace for a night of drinks with friends, or with a pair of jean shorts during the day.
And, don't forget about a light cardigan. It comes a long way during Spring vacation. Remember weather always changes and some nights could be cooler than others. It’s always good to be prepared.