In a large pot, add enough water to cover shrimp (3-5 qts. depending on pot size) with vinegar and spices. Cover and bring to a boil.
Add shrimp to the seasoned, boiling water. Stir often from bottom to make sure shrimp is rotated around pot.
When shrimp turn bright orange and some have curled in half, taste or cut one of the larger shrimp in the batch. If it is done, the whole batch is done.
Pour shrimp into a colander to drain. Sprinkle shrimp with additional Old Bay Seasoning and gently stir (optional)
Allow shrimp to sit for a few minutes before serving.