Rub the pork shoulder thoroughly with sea salt, black pepper, ground cumin, and dried oregano to ensure every inch is seasoned.
Place the seasoned pork into the slow cooker, then add the minced garlic and pour the orange juice over the top.
Set the slow cooker to low and cook for 8 hours, or until the meat is incredibly tender and pulls apart easily with two forks.
Shred the pork into bite-sized pieces and transfer to a large skillet over medium-high heat with a splash of the remaining slow cooker liquid.
Sauté the shredded pork until the moisture evaporates and the edges become beautifully golden and crispy.
Warm the corn tortillas in a dry skillet over medium heat for about 30 seconds per side until they are soft and pliable.
Divide the crispy carnitas among the tortillas and top with fresh avocado slices, diced red onion, and chopped cilantro.
Finish each taco with a bright squeeze of lime juice before serving.