I'll tell you my personal experiences as a fisher/cooker.
Fishing up your own fish for cooking is a great duo craft. There's no "get rich quick" schemes like synthing cursed gear and hoping for an HQ, it's all honest (Unless you fish bot, which I've caught 2 LS mates doing so far) hard work, with no risk involved. (Who cares if you lose a squid in a failed synth, but you'll definetely miss that Angel Skin)
The only problem is trying to get that Fishing Skill up.. that is a doozy. I've been fishing for a couple months now, not regularly or for long periods of time, and thus far I'm about 18.7ish. I spent about 2 hours fishing yesterday and got .4 skill ups, which for me is an average day.
If you go down that route, you'll definetely want to take a look into Pelican Ring. So far I have yet to get it, but after monitoring the scoreboards for a few weeks I've determined that on average, 20-25 people play weekly on my server. In order to get the Pelican Ring, you need to score in the top 20, leaving you with a good chance that you'll get your ring.
The great thing about skilling fishing is that you can make a pretty penny off of it. Moat Carps, Nebi's, Shall Shells are all great profit pre 50. You can synth a stack of two of Nebi's every week for Fish Mithkabob. And boy have I got a lot of Nebi's to synth. I tried synthing 5 stacks of Nebi's in a single day... I ended up flooding the market and dropping the price by 1/3 a week later, and I'm still trying to finish selling them. Most people go for Tacos so try to avoid synthing Nebi's, it's probably best just to sell em on AH to Alchemy users, saves you a lot of hassle.