This is the section most travelers wish they had read first. Overpacking is the number one complaint we hear from guests on their first day. Less really is more when you are moving between regions.
Jeans: They never fully dry in the humidity. Swap them for quick-dry pants or shorts and thank yourself on day two.
High heels or dress shoes: You will not need them. Even nice restaurants in Costa Rica are casual. One pair of clean trail sandals does the job.
Too many shoes: Three pairs maximum: waterproof sandals, trail shoes, and flip flops. Shoes are heavy and take space.
Non-reef-safe sunscreen: It is prohibited in several reserves and harmful to marine ecosystems. Bring reef-safe from home. Brands like Raw Elements and Badger are good options.
A hair dryer: Almost every hotel and lodge provides one. Leave yours at home.
Valuables you cannot afford to lose: Leave the expensive jewelry and the laptop you need for work. Use your trip as a proper break.
Cotton everything:Cotton absorbs moisture and stays wet all day. Pack synthetics or merino for everything except maybe one casual outfit.