Never over boil shrimp or crawfish. Makes them mushy. I put them in rolling boil water/spices then cut the heat and let them sit for 8-10 minutes before putting them on the ice.
Just be careful. You'll have a lot of boiling water. This is sorta kinda why we do this outside. (Worst yankee with shrimp story I ever heard was the one where the lady boiled a gallon or so of oil instead of water and then put in a box of frozen shrimp. After the explosion the condo caught on fire.)
The shrimp were fantastic last night. Boiling for a minute, then letting them sit in the water for another 10-15 minutes is definitely the way to go. However, I used the Zatarain's crab/shrimp boiled bag. While it smelled really good while cooking, I can't say a lot of the flavor was transferred to the shrimp. Next time I will use more of it, or i'll try the liquid shrimp boil as well.
You got it tiga! I did add some cayenne pepper.......not enough though. However, my cocktail sauce was kickin......