I like to wash my shrimp by placing it in a bowl of ice water and about 1/2 tsp of salt for a few minutes.
Zest the lime and slice in half.
Slice one lime half into six wedges, reserve four wedges for garnish.
Peel, crush and finely dice the garlic.
Wash and dry the jalapeno, and slice into thin rounds.
Wash, pat dry and coarsely chop the cilantro. You should have about 1/3 cup. Remove the long, woody stems, but the thin stems at the top are fine. Reserve 1 tbsp for garnish.
Drain the shrimp, rinse with fresh water, pat dry and return to clean dry bowl.
Squeeze juice from the lime half and two wedges over the shrimp.
Add garlic, half of the lime zest and half the cilantro to the shrimp.
Add 1 tbsp olive oil to the bowl with the shrimp, mix and allow it to marinate for a few minutes.