First thing is, if you want to cook the shrimp in the lime juice you’ll have to put them in the lime juice at least 8 - 10 hours or until they turn pink. You may also boil them to the point when the just turn pink, take them out of the hot water and chilled with some ice and cut them in have. Once you have all your ingredients prepared, it is a simple matter of putting everything together. After everything is cut and ready to go simply take a mixing bowl, add about a tea spoon of salt and 2 table spoons of vinegar. Follow by adding the all the shrimp, diced onions, dice tomatoes, cubed avocados and add as little or as much cilantro as you like, cilantro can some times have a lot of dirt so you want to wash it under running water, shake the water off and let it dry before dicing it. Finally add the lime juice, you may need more lime juice. If you are cooking the shrimp in the lime juice make sure that all the shrimp are cover with the lime juice but if the shrimp are already cooked you don’t need as much. Take a mixing spoon and mix all the ingredients until the are evenly distributed, take a little taste and check for salt if it needs some more add a little more and mix it again. If its too acidic ad a little bit of orange juice and it is ready to serve.