Cut the avocados in half & remove the pits. Reserve one pit if you plan to store the guacamole to be used later. Using a small knife, hold an avocado half in one hand (by the skin) & carefully cut a grid pattern into the flesh. Scoop the flesh out into a medium bowl. Continue until all of the avocado has been scooped out.
Before you cut the line, roll it between your hand & the counter for 30 seconds to loosen the fibers. Juice half of the lime over the chopped avocado. Using a fork, mash the avocado to your desired consistency. I like to leave some chunks whole but mash the majority into a thick paste. Add more lime juice as needed to achieve desired consistency & taste.
Chop the tomatoes into small/medium diced pieces, removing the juicy parts. Dice the onion into small pieces. Finely dice the jalapeño; remove most of the seeds & membrane. Add the tomatoes, onion, & jalapeno to the mashed avocado. Add half of the chopped cilantro & all of the seasonings. Gently stir everything to combine.
Taste & add more cilantro + seasonings if preferred. Store with 1 pit for freshness. Use within 3-5 days.