There's a lot to be said about fishing with nets and trawling with boats, but I'll leave that for another thread. I used to fish a lot as a kid, but I've since lost my pole so I haven't done it in years, so please correct me where I'm wrong if you're a hobby fisherman.
Anyway, fishing is currently dull because it's always the same and it doesn't involve any decision making. What makes fishing interesting IRL is that there's a huge number of factors that determine your success, and just how these factors affect your success is very open to guesswork. I'd like fishing in H&H to be like that. I want fishing to be based on randomness, with various things weighing the RNG. I want a situation where some people swear that the best way to catch a trout is to fish with an earthworm at midnight on a full moon, while other people are sure that fly-fishing at noon is the best way to do it. With a large number of factors involved, it'd be nearly impossible to deduce what the math behind fishing is, and IMHO a bit of mystery makes things more fun.
RNG should be weighed by environmental factors such as the time of day, season (when it's added), weather (when it's added), phase of the moon and location. By location I mostly mean river vs lake, depth of water and distance from the shore. But there should also be better and worse fishing spots (different for each fish specie, mind you) within one body of water. It should be possible to artificially improve a fishing spot by throwing feed into the water at one location. It's commonly done IRL. Artificially improved fishing spots should favour the bait that's same as the feed used to make the spot. These spots should revert to their natural state after a while if the feeding of the fish is discontinued.
Bait-wise, there should also be a huge number of options. Basic bait-less pole should be good enough to catch some perch, but it should go faster if you use bait. Bait can either be combined with the pole to make a temporarily improved pole, or it can just use the most recently placed bait in your inventory if the former clashes with the game engine. Bait should be expendable, most should be single-use, but some should be reusable until RNG decides that it got ruined. Bait quality should influence the quality of your catch and the time it takes to catch it. Bait type should heavily influence the type of fish you catch. Some baits that come to mind:
- Earthworms. You get them from time when you dig for soil. You can also raise them in compost piles, which can double as a means of producing good quality soil from stuff like good quality leaves and straw. Single-use.
- Worms. Let a piece of meat spoil to get them. Meat spoiling on it's own would be kinda annoying, so maybe you should have to put it on a herbalist table for it to spoil. Single-use.
- Bread. Combine a loaf of bread with some water to get a fairly large number of baits. Single-use.
- Artificial fly. Use a nugget of wrought to make a dozen or so hooks. Use a hook with feathers and string to craft a fly. Best flies should take silk filaments and rare feathers (when we get eagles and stuff) to craft. Crafting flies should be heavily influenced by Psyche. Multiple-use.
- Spinners. Take 3 hooks and a metal nugget to craft. More valuable metals make for better spinners. Psyche and smithing should heavily influence the quality. Multiple-use, and they should last a long time.
Now, I've already mentioned there should be new fish. These should include trout, pike, carp, eel, catfish and others. The types of fish aren't really that important. What is important is that there should be a fish for every stat, so that newbs can eat a balanced diet from the start, and to give them means of producing tradeable goods. Obviously, some fish should be more rare than the other - Psy fish for example should be a fairly rare catch, as Psy is meant to be a hard to raise stat.