I never mess around with breading mix anymore.  It's messy and just makes for more effort to cook and clean and adds (unneccesary) calories.  

I just season the fillets with either cajun seasoning (Paul Prudhomme's Seafood Magic is awesome), lemon pepper, or dill and fry them in a 50/50 blend of squeeze margarine and oil.  You use a lot less oil/margarine this way, too.

The hidden benefit is that you don't pack the weight or bulk of breading mix and the extra oil that it consumes.  Breadings soak up a LOT of oil and you need more in the pan to cook with so there's more waste.  Try both methods side by side and see how much less oil you use.  I just got off a trip where we had fried fish for 2 people for 2 nights, plus a few other miscelleneous uses of the oil.  I used less than a cup of oil total on the trip.  Add in the half a cup of squeeze margarine and it's still less than most would use for a single fish fry using breading.