Slice the avocado in half lengthwise. Put the half with the seed in your hand and gently squeeze the skin from either top-to-bottom or side-to-side; then often times the seed will come loose. Once the seed is removed, use a dinner-size spoon to scoop the flesh from the skin and add it to a medium size bowl.
To the bowl, add lime juice. Mash the avocado gently leaving some chunks. Add the salt, pepper, red onion, garlic, cilantro and tomatoes. Gently mix together.
Do a taste test and add more salt if needed (salt really makes the flavors all tie together so make sure to add enough).
Garnish with lime wedges and sprigs of cilantro. Serve right away.