In a large bowl, combine juice from 1 lime and the flesh from 3 avocados. Toss to coat.
Remove the avocados from the lime juice. Reserve one tablespoon lime juice.
Using a potato masher, mash the avocados until you've reached your desired consistency. Add reserved lime juice back in. Stir in salt, cumin, and cayenne pepper.
Fold in onion, tomatoes, jalapeño, cilantro, and garlic.
Allow to sit at room temperature for about an hour for the best results. Serve with tortilla chips or veggies of your choice. Make sure to store any leftovers in an air-tight container.