Prepare the flavored butter mixture: In a small bowl, combine the very soft butter, minced garlic, fresh lemon juice, and fresh parsley leaves. Stir and set aside.
Heat 1 tablespoon oil in 12-inch skillet over high heat until the oil is shimmering. Meanwhile, toss shrimp, salt (I add about 1/4 teaspoon, add to preference), lemon herb seasoning, garlic powder, and parsley flakes in a medium bowl.
Add half of shrimp to pan in single layer and cook until spotty brown and edges turn light pink, about 1-3 minutes (longer depending on size of shrimp).
Remove pan from heat. Using tongs, flip each shrimp and let stand until all but very center is opaque (about 30 seconds). Transfer shrimp to large plate. Repeat with remaining tablespoon oil and shrimp. After the second batch of shrimp has stood off heat, return first batch to skillet along with the flavored butter mixture and toss to combine. Cover skillet and let stand until shrimp are cooked through, about 1 more minute.
Serve with lemon wedges and fresh parsley as desired.