The Best Packing Guide for Traveling, Living, or Studying Abroad in Costa Rica

First I should start with some things to not bring to Costa Rica. Namely, this list includes things that would be damaged by extreme humidity or heat, which are pretty much Costa Rica's middle names. So: leather shoes, clothes that can only be dry cleaned (besides humidity damage, I didn't see a dry cleaners outside of San Jose), precious books, your collection of rice paper, etc. Don't bother with chapstick or other remedies for dry skin; it's so warm, you won't get dry skin unless you have a disorder. And specifically for ladies: don't bring any Plan B-type things--they are considered an abortion in Costa Rica and are illegal to have and/or consume--or dangling purses--easier to steal. 

The rest of this post will just be in a handy list format, since more people are concerned with what to bring:

Clothing

Raincoat (don't you dare skip this, especially if you're going between April and October)

Sneakers you can get filthy

At least one pair of comfortable walking shoes

At least one pair of jeans (Costa Rican men don't really wear shorts, Costa Rican women wear pants more often but shorts aren't unusual)

Shower shoes (if you plan to frequently stay in hostels)

Toiletries 

[almost all toiletries are imported and thus very expensive in Costa Rica, so balance the weight of your bag with bringing as many of them as you can fit]

Toothpaste

Shampoo/conditioner

Bar soap (easier to transport than containers of body wash)

More sunscreen and bug spray than you think you can use

Makeup

Extra prescriptions

After-sun lotion (for when you inevitably get sunburned)

Tums and Immodium (seriously)

Bath towel (if you plan to stay in hostels)

Miscellaneous

Sturdy, collapsible umbrella

Books (to read on bus rides)

Backpack or duffel bag (for day/weekend trips)

Eye mask if you can't sleep when it's bright (sunrise is at about 5 AM all year)

Wallet with a zip pocket or a coin purse (many transactions involve just coins)

Small Spanish-English dictionary

A few ziplock bags to protect your electronics while out walking (rain is so good at destroying stuff)

Technology

Some kind of device to utilize the internet: tablet/laptop/smartphone

Plug adapter for 3-pronged device chargers to fit 2-prong plugs

Extra batteries if needed for cameras/razors/etc. (they're so expensive in CR)

Small flashlight

Camera (for posterity)