My time in Costa Rica was amazing!! I worked hard (their school system can be kinda intense) but 3 1/2 day weekends on the Caribbean are amazing!!! It was harder re-adjusting to America when I got back than it was getting used to Costa Rica. Pura Vida is a way of life.
Packing: (SEP-DEC) Clothing – San Jose is damp, Caribbean is humid. Generally pack for AZ winter (sweater in the am, tank top after noon). jeans are good most nights, but cargos/breathable fabrics are better. Bring comfy shoes for walking!!!! Umbrella and waterproof purse/backpack are the best investments EVER. Sun screen and Bug Spray only needed outside of San Jose. Bring Peanut butter. It’s super expensive there, so bring some. You’ll miss it. Trust me.
Safety: Petty theft is a problem in Latin America, but nothing much worse than that. You probably don’t look Tico/Tica… so just be AWARE and be smart… Taxis are expensive BUT DO IT!! People I knew got robbed after dark! Get friends together and split it. Be cautious – roads are ridiculous and J-Walking is common law.
Food: Try the food!!!! Seriously!!! Pan integral with guyabana jelly. And ceviche – with enough hot sauce and mayo to turn it pink. So. Good. Gallo Pinto and Arroz con Pollo are obvious traditional favorites.
The Homestay Experience: It's fantastic. My "Mama Tica" was a wonderful woman (and an even better chef!), I really felt like a part of the family while I was there. She went out of her way to help me, and always had suggestions for things to do out on the town. I've studied Spanish for a long time, so I didn't struggle with that too much, but she worked with the other student who stayed with us(who had less Spanish) really well too.
Travel Advice: You’ll have enough time on busses to do homework (So don’t worry about it! ¡Pura Vida, Mae! :P) In addition to the ISA trips, be sure to hit the following: (1) Puerto Viejo, Limon on the Caribbean side for surfing and snorkeling – chill little surfer town (2) Playa Hermosa for shorter trips. It’s the closest NICE beach to San José. Just south of Jacó, which is really popular for some reason I don’t understand – it has painful rock beaches and dangerous surfing… (3) Montezuma for absolutely beautiful nature!! Waterfalls, forest – it’s surreal. (4) Chirrpó for a really cool & challenging hike – it’s one of the highest (if not THE highest) mountain in CR… (5) Also, try to hit one of the community-based ecotourism groups while you’re there. Ecotourism is HUGE in Costa Rica and this is the purest form! (I did field research on efficacy of ecotourism groups while I was there.)
General Advice: Yes, you’ll miss people back home, but don’t let it get in the way. Skype is FANTASTIC, but you shouldn’t be hooked up 24/7. That being said - live it up! Learn as much as you can, try as many things as you can, make as many friends as you can… Don’t pass up an opportunity; you might not get to go back.