Adding spices before or after frying?
Do you mean sautee? Or deep fry?

Typical deep fry recipe would be to incorporate spices into the flour: add your salt, pepper, paprika, etc to the batter, then fry.

If you sautee, your chicken strips should be seasoned like follows: first, rub in a small to medium amount of kosher salt (not table salt). Let sit for 15+ minutes to season / brine the meat. Best would be a water brine, but I'm guessing that's too fussy for you.

Now, cook up the chicken strips in the pan. Most dry spices I could imagine adding could go in towards the end of the sautee, stuff like cayenne and so on. Garlic or onions would be added first before the chicken, and cooked until soft, but not too brown.