Cash

Flip-flops/Sandals

Water shoes (if you plan on snorkeling or rocky beaches)

Comfortable walking shoes

Swimsuits 

Cover-up(s)

Shorts 

T-shirts/Tank tops 

Sundresses/Casual dresses 

Pants/Jeans 

Light sweater or jacket

Underwear

Socks

Pajamas

Sun hat

Sunglasses

Beach bag

Jewelry (consider bringing less valuable pieces)

Sunscreen (high SPF)

After-sun lotion

Insect repellent

Shampoo, conditioner, soap

Toothbrush, toothpaste

Deodorant

Any personal medications

Passport/ID

Phone and charger

Camera and charger

Reusable water bottle

Snorkel gear (if you prefer your own)

Books/Entertainment

Small first-aid kit

Dry bag (for electronics near water)

Beige/Nude colored semi formal attire for dinner