Vacation packing is almost always the most stressful part of a trip. For me, whenever I'm packing, I'm also automatically taking a forward trip in time to when I'm unpacking, which is the bane of my existence. Therefore, it's important for me to pack light, with cute things that can be worn in multiple ways. On every single trip I go on, whether it be tropical or city-bound, I always, always, always pack multiple maxi dresses. A good maxi can be dressed up with a leather moto jacket or dressed down with a denim jacket. You can throw a sweater on over it if the night gets chilly or a chambray shirt to look low-key. They also don't have waistbands, so you can eat to your stomach's content.
Another great tip is to bring easy, breezy versatile separates that you can mix and match. One of my favorites is this lace top and white skirt set. You can wear them together or you can wear them with other separates to make multiple outfits. I wore the lace top with shorts and the skirt again with a sweater. It's important to have all your outfits adapt to any weather changes.
One of my favorite pieces that I've worn many times on tropical vacations is a poncho-style top. A poncho can be worn during the day with some jeans or you can toss it over a swim suit and wear it as a cover-up to the beach or the pool. It's comfortable and chic, however you wear it.
The fewer things you have to worry about before vacation, the better, so keep the packing light and easy. Plus, you want to leave room for some good vacation purchases!