Number 1 - remember to pack items that are comfortable! Number 2 - versatility is key.
Lets get into some inspirations for you:
A maxi skirt - easy to pair with a tank top, crop top, slouchy tee, even a swimsuit. Elevate by night with a denim jacket, knit cardigan or lightweight blazer for dinner. Pair with metallic sandals, sneakers, or espadrilles.
A chambray shirt is a wardrobe staple. Pair it with anything all Spring and Summer; denim shorts, linen pants, even your maxi skit! Same shoes above apply. (Denim on Denim is called a Canadian Tuxedo and it's totally a thing)
A wrap dress is probably one of the easiest pieces to dress up or down... all you need to change is your shoes, jewelry, and handbag. Tip: adding a pop of color on your lips, shoes, or clutch can make a huge difference.
A jumpsuit has the same effect as a maxi dress, making is easy to pack for any destination.