1. Choose the right fish: When selecting a fish for grilling, opt for firm, thick fillets or steaks such as salmon, tuna, or swordfish. These types hold up well on the grill and are less likely to fall apart during cooking.

2. Clean your fish: Make sure to clean your fish thoroughly by removing scales, gutting it (if not already done), and rinsing with cold water.

3. Prepare the grill: Preheat your barbecue to medium-high heat. For charcoal grills, pile hot coals on one side of the grill for direct heat and leave the other side with fewer coals for indirect heat. For gas grills, turn on one side to medium-high and leave the other side off or on low heat.

4. Oil the grate: Wipe your grill grates with a cloth or paper towel dipped in cooking oil to prevent sticking.

5. Dry the fish: Pat both sides of the fish dry using paper towels to remove excess moisture and help it cook evenly.

6. Season the fish: Lightly season both sides of your fish with salt and pepper, or use a marinade or dry rub for additional flavor.

7. Add extra flavor: Add flavor by placing fresh herbs, lemon slices, or soaked wood chips directly on the grate or in a smoker box.

8. Get ready to grill: Place aluminum foil or a grill mat under parts of your fish without skin to prevent sticking and promote even cooking.

9. Start with high heat: Place the fish skin-side down (or oiled side if skinless) over direct medium-high heat for 2-4 minutes to sear and crisp the skin.

10. Flip carefully: Use a spatula to gently lift and flip your fish onto the indirect heat side of the grill.

11. Adjust cooking time: Fish cooks quickly and can overcook easily, so adjust your cooking time based on the thickness of the fillet or steak. Generally, each inch of thickness requires 10-12 minutes to cook.

12. Check for doneness: Test for doneness using a fork by gently flaking the fish at its thickest part. If it flakes easily and has turned from translucent to opaque, it’s ready. Optionally, use a meat thermometer to check for an internal temperature of 145°F (63°C).

13. Rest the fish: Remove the cooked fish from the grill and let it rest on a clean plate for about 5 minutes to let the juices redistribute and continue cooking.

14. Add finishing touches: Squeeze lemon or lime juice over your cooked fish or add a sauce or garnish to enhance the flavor.

15. Serve and enjoy: Serve your perfectly grilled fish with your favorite side dishes like grilled vegetables, salad, rice, or potatoes.

Follow these 15 steps to enjoy delicious and tender fish cooked to perfection on your barbecue, whether you’re hosting a backyard cookout or simply enjoying a casual meal with family.