It’s unlikely that you’ll forget your wedding dress when you come to Costa Rica. You might forget everything else — but your dress is coming with you so we don’t need to say any more about that.
It also doesn’t really matter what kind of dress you choose. I’ve seen women get married on the beach in everything from simple knee-length dresses to extravagant ballgown-style dresses. Just because you’re having a destination wedding doesn’t mean you have to give up on your dream dress.
However, how you bring your dress is an important thing to think about. Unlike most clothing, you can’t just toss it in your bag and expect it to look amazing when you get here. Fold it properly, and I highly recommend using a garment bag to keep it protected. It won’t be wrinkle-free when you arrive, but the humidity here helps to iron it out. Just be sure to get it out and hang it up as soon as you get here.
The same thing for the groom’s suit, although this is typically easier.