Homemade Guacamole

3 medium ripe avocados, peeled and cubed
1 garlic clove, minced
1/4 to 1/2 teaspoon salt
2 medium tomatoes, seeded and chopped, optional
1 small onion, finely chopped
1/4 cup mayonnaise, optional
1 to 2 tablespoons lime juice
1 tablespoon minced fresh cilantro

Mash avocados with garlic and salt. Stir in remaining ingredients. Makes 2 cups.