A soft suitcase (a carry-on if possible to avoid problems of lost or delayed luggage)

Day pack, Water bottle

Comfortable pants, good for hiking, Hiking shorts, if you prefer shorts  ( not customarily worn by Ecuadorians)

T-shirts or short sleeve shirts, Long-sleeve shirts, Long-sleeve jersey or turtle neck that can be used for an extra layer

Waterproof rain-gear that folds small

Warm sweater or jacket (fleece is great)

Thermal underwear that can double as pajamas, or warm PJ's

Bathing suit

Good walking shoes or lightweight hiking boots or hightop sneakers (no break-in required)

A extra pair of lightweight sneakers or comfortable shoes in case of rainy or muddy conditions

Heavy socks

Sun hat

Camera, film and necessary batteries,

Binoculars (compact and lightweight)

Bandannas

Swiss Army type knife

Sunglasses

Toilet kit

Small flashlight

Sunscreen

A good book or two