Blackening foods is just a technique of cooking foods at a high heat to sear the outside. By doing so, the natural sugars caramelize and creates the best flavor. You can use your choice of seasoning as a blackened seasoning. Some typical favorites would be paprika, cayenne, garlic, onion, salt and pepper. Choose how much of each to use. I suggest following the basic recipe and stir the spices together. Give the seasoning a little taste and see if you want to add more of a spice.