Slice each avocado in half, remove the pit, and scoop the flesh into a medium size bowl. Add the lime juice and toss to coat. Set aside.
Slice each tomato into quarters and, using a spoon, scoop out the seeds and soft inside parts. Cut into small dice and add to the avocados.
Add the onion, cilantro, jalapeño, and garlic. Use a large fork or potato masher to mash everything together to desired consistency. Add salt, taste, and add more if necessary. Guacamole is best served right away, but leftovers can be stored in the refrigerator, covered tightly with plastic wrap in contact with the surface of the dip. Enjoy within 3 days.