I went to Costa Rica about 4 years ago and learned how to make some really good guacamole.
1 diced tomato
1/2 cup chopped red onion
1/4 cup cilantro
1 whole diced Jalapeno
2 1/2 tablespoons minced garlic
1/4 cup lime juice
Mix all ingredients together. Stir in half the lime juice then put the other half on top to prevent avocado from browning. Keep refrigerated until ready to eat.