Don't overcrowd the pan. If the shrimp are stacked, they steam. Work in batches if necessary. Butter goes in last. Starting with butter will burn it — oil can take the heat; butter is the finishing move. Dry the shrimp even if the package says 'pre-dried.' They are always wet. Pat them for a full minute with paper towels. Storage: Cooked shrimp keep in an airtight container in the fridge for up to 2 days. Reheat gently in a hot skillet — not the microwave. Freezing cooked shrimp is not recommended.