Turning down your video settings can make it easier to see the fishing line, which between the time you cast and the time your fishing bobby fades into existence, this can be handy in immediately knowing where your bobber has landed (inside or outside of the Pool of Tasty Fish). Turning down specular lighting and full-screen glow effect can dramatically make your fishing line's color more distinct, as with these two features on your fishing line will be colored according to the color and lighting of the surrounding environment, making it harder to see.
Turning off the weather effect completely if STV is raining during the tournament also helps.
