Gather your ingredients.
First, rinse your fish off with cold water and pat dry with paper towel.
In a small bowl, add salt, sugar, garlic and onion powder. Stir until blended.
Place fillets at your workstation.
Press rub onto each fillet, as evenly as possible.
Cover fish in plastic wrap and refrigerate for a few hours. I usually place in the fridge for about 3 hours. Any longer and the fish can have a salty taste.
Remove from fridge and rinse off and pat dry each piece of fish.
Place on baking sheet and refrigerate again for another 3 hours or so.
Preheat your smoker to 200 degrees.
Allow fish to smoke for about 2 hours, maybe 3. Bigger fillets may require a little more time. No more than another hour.
Remove fish from smoker.
Serve immediately and enjoy every bite!