yea when it goes down you generally should set the hook.... the best tip for trout fishing is to go out alot by yourself with no distractions and learn how to catch the fish get in tune with them. i have calenders from years ago where i would write down the number of fish caught, time of day, temperature, cloud cover, water colour etc etc. i can know catch well over 100 or more rainbows a year and i dont care if know one beleives me because its just the internet...