Sneak fishing is simply casting sneak while you fish so that you can pull up monsters w/o getting aggroed, and in some cases, not get aggro by the surrounding mobs. Stamina fishing is knowing roughly what sort of fish/item is on your line by the way the rod moves and stamina drops. You know if you get a rusty bucket, the line almost never changes position - stays centered a lot and stamina drops very fast. Then you get on the ferry and catch presumably a very strong monster or a legendary fish and the rod whips left and right 2-3 times a second and you don't stand a chance. With a small margin of error, it's pretty easy to start knowing what's on your line before you ever reel it it. I'm currently fishing a trio of Cone Calamary, Noble Ladies and Bluetail, and Cone Calamary acts more like a rusty bucket, whilst Bluetail rocks the line quite a bit. Noble Ladies are somewhere in the middle but have high stamina. If I cared to, I could probably limit myself to one fish.