I do this at least once a week and found this to be the best way for salmon, trout, red snapper, cat fish and it's very easy and quick. After you wash your choice of fish, put it a bowl or container. Then drizzle about a tsp of balsamic vinegar, tsp of olive oil, some red wine or sherry vinegar and lastly sprinkle some sea salt and fresh cracked pepper or a seasoning mix like Lawry's. This is for a 6 oz piece so adjust to your liking for bigger portions but it doesn't have to be exact. A little goes a long way with fish, it's not resistant like pork or chicken.
Then just turn the fish around the bowl to get everything distributed and let it sit for 10 min upwards to an hour but anymore than that the fish will be too saturated and lose it's integrity. Now here's the easiest and least messy part to cook it. If you have a toaster oven use the broiler and in about 8 min you will have a piece of fish that's just as good as Red Lobster. And that's how most fish house cooked their fish through a broiler.