A lot of the frozen shrimp in big stores are white and shrimp and are no good. Tiger prawns are alright.
Try to find some 10/15ct or 16-20ct brown shrimp. They are getting expensive, been a terrible year for shrimp. Right now were selling 10/15ct for $14.99 and 16/20 for $11.99. The 10/15s are expensive, around $10lb my cost right now which sucks.