Up until Mist of Pandaria, the fishing and cooking professions were some of the most heinous professions to level. Fishing was simply boring as you took ages just grinding through zones until eventually you couldn’t push any farther. Cooking really only saw benefits for raiding but the rest of cooking practically was useless, unless you enjoyed achievements. Worse yet, cooking was painful in that if you didn’t bother leveling up cooking as you leveled, you pretty much was forced to return to older zones to grind out the ingredients just to get a few more skill points. Otherwise, more than likely you would have to spend a ridiculous amount of gold on materials as people just had little patience trying to get the materials themselves.
Mist of Pandaria though made cooking actually useful, injecting all types of buffs with the food you create. Leveling cooking up until 525 is extremely easy as you can get all the materials from the trainer. All you require is gold (around 340) and 42 Golden Carp. As you level, you probably will acquire many of the ingredients from slaying beasts around the land. The hardest thing initially will be having the vegetables for the Pandaren recipes once you hit 525 in cooking and then the fishing ingredients.
To me leveling cooking and fishing pretty much go hand in hand these days. One of the nice things they added a few patches ago was a quest giver near the Halfhill Village who provides fishing training. You just have to get a few Golden Carp from the neighboring river and you’ll be on your way. But rather than forcing you to level all the way to 525 before seeing Golden Carp, you now will start seeing Golden Carp as a kind of “trash fish”. This is far better than just discovering worthless grays as in the past and Golden Carp still can fetch some easy gold on the Auction House.
So I feel that with the ease of leveling both skills, it’s pretty much worth investing the time as you quest and level up to also delve into both. I feel that you probably should grab fishing (if you don’t have it) prior to entering Pandaria. That way as you level through the Jade Forest and other zones, you can take the time to grab the occasional fish you might spot from the random ponds. Also, because there are three dailies at 90 which gives 3 skill points for turning them in (along with some gold and valor points), you have even more ways of leveling fishing than before.
Pretty much what I do is seek ponds as I level and save any excess fish, even if the core stat from a cooking type isn’t really relevant for my class. That way, if I’m a bit low on fish ingredients while I level on a single toon, I might have extra materials on my other toons. Also, I try to save meats I find from beasts just in case someone might need an excess. A lot of meats that you gather might seem useless and a waste of bag space, but they’ll come in handy once you hit higher levels of cooking.
Also with regards to fishing, I enjoy leveling it while I’m waiting for a queue. If you get burned out on dailies, fishing offers a relaxing and lucrative opportunity to be productive. Pop on some tunes, check out online videos or other sites and you’ll find fishing to be worth it in the end.