Almost any fish can be grilled, as long as you grease the grill and the fish itself to prevent sticking. Thick steaks or fillets of firm-textured fish, such as salmon or swordfish, can be placed directly on the grill. Swordfish, tuna and other "meaty" fish also work well in kabobs. For more delicate fish, such as bluefish, butterfish or whitefish, use a well-greased grill basket or a piece of greased heavy-duty foil. You can improvise a grill basket by sandwiching the fish between two ordinary cake racks and wiring them together.