Ok, I'll share my "secret" recipe with you since you are a "fellow Texan".

But don't tell anyone!
Go to your local grocery store.
For each pound of shrimp, crawfish, etc... purchase one package (2.65 oz) of "Louisiana Fish Fry Products" brand of "Cajun Etouffee' Mix".
Follow instructions as listed on the back of the package. YUM!
The only alterations we ever make is that sometimes, we saute' some diced banana peppers in the butter B/4 adding anything else. You could add spicier peppers if you like it really spicy!
If you can't find it at your local store, I'll be more than happy to send you some. Once you have the package in hand to show them what you are talking about, the store could probably start stocking it. When we lived in Ga. and couldn't find it, my MIL sent us some from here in Lousiana and then the mgr. at Publix started stocking it.
(wonder if this will qualify me for another Chef Guy??

)