TIP:
If the fish isn’t pre-packaged, check the gills—they should be red if fresh. Also, look at the eyes; they should be clear and bright, not white or sunken, which means they’re not fresh.

Even if the store cleans the fish, always check that it’s properly scaled, the gills are removed (many times they’re not), and inspect the inside of the belly. There’s a thin membrane—if you see the bones, it’s good, but if not, make a small cut to remove the membrane and wash thoroughly.

If you see black along the inside edge of the belly, scrape it off with a knife to avoid bitterness.

Make 3 diagonal cuts on each side of the fish and pat dry with a paper towel.

In a medium-deep tray, mix all the seasonings well, or just use lemon, salt, and pepper if you prefer.
This is just a suggestion—feel free to adjust the seasonings to your taste.

Rub the seasoning mixture all over the fish, inside, outside, and into the cuts.

I like to marinate it overnight, turning it in the morning so the flavor soaks in evenly. But you can also cook it right away if you prefer.