Rinse shrimp and pat to dry. Remove tails if needed, and chop into small pieces.
Add chopped shrimp to a large bowl and squeeze in fresh lime juice, until tops of the shrimp are just about covered. Set aside and let this marinate for approx. 10 minutes or until shrimp starts to turn pink.
Meanwhile, chop red onion, cucumbers, tomatoes, cilantro, and jalapeño (if using) into small pieces - around the same size as your shrimp. Remove the seeds from the jalapeño if you prefer less spice.
When the shrimp is looking a little more pink, add chopped veggies to bowl and stir gently to combine.
This part is to your taste preference - add a splash of orange juice, a quick squeeze of ketchup, and a few drops of hot sauce, and stir to combine. Taste and adjust accordingly, add salt if needed. Gently fold in avocado chunks.
Serve immediately with tortilla chips, or store in the fridge for up to 1-2 days.