I’ve gone through all of the professions in MoP, so let’s talk about what the optimal pairings are and whether the profession requires you to level up or not.
Spirits of Harmony
We can’t really get into this without considering Spirits of Harmony. All Epic gear as well as a good chunk of other recipes require spirits of Harmony to craft, and if you want to be active in these markets you will need to have a way of farming spirits. Anyone can do it by killing mobs, and you can get more per hour by using potions of luck. The professions that have the largest reliance on spirits are: Tailoring, leatherworking, Inscription and blacksmithing. These are the top choices to have on your main or a character you plan to level up and play quite a bit early on.
Great on alts
Some professions are great on alts, this is either because you can unlock and craft all the recipes or because of daily cooldowns. Tailoring is in this boat as well with the Imperial silk cooldown, as are Jewelcrafting, Inscription, Alchemy and Enchanting.
My suggested combinations
Essentially we will make a couple of archetype combinations. First is the main crafter. This is your main or second main that you will level up very early and can farm Spirits on. Here I would go with Blacksmithing and then one of inscription, leatherworking or tailoring. Blacksmithing is the top choice due to the Klaxxi weapons, even if they are outclassed by other options they are a GREAT early gearing option and will sell well. The second one is personal preference, there are arguments for all 3 professions, the main thing is that they can all take advantage of being max level by unlocking recipes or farming Spirits. The second character you level to max should have the other two ideally, but you could also throw in Jewelcrafting for the panther mounts specifically.
Alt builds
We will split it by cooldown alts and main alts. The first thing you want to do is cover every profession. Generally it does not matter too much which professions you combine, unless there are similarities in reputations for recipes. That is not really the case in MoP so any combination is fine. I do think Alchemy and jewelcrafting play well together if you want to transmute rare gems, and then you can enchanting and engineering with whatever. There’s also some merit to combining enchanting with tailoring for disenchanting shuffles, but it depends on what your main has as well.
Cooldown builds
There are several very valuable profession cooldowns in MoP. For the first patch the top ones are Imperial Silk for spellthread and tailoring epics, Living Steel from alchemy and darkmoon cards from Inscription. In particular the darkmoon cards will make large alt armies of scribes very interesting to help players get their trinkets ASAP.
Finally let’s look at my plan:
My main will be my warlock, which I will play for PvE. I plan to keep the professions I currently have in Engineering and Tailoring.
Then I have my DK which is engineering/JC right now. I will likely swap out engineering as I don’t care about duplicating that. Most likely I will go for inscription in stead. Then I have my rogue which is alchemy/blacksmithing. I’ll keep that as is, and I will also keep my enchanter/scribe mage. I am unsure if I want to add leatherworking or if I want another inscription cooldown on my DK. There’s also a potential choice to swap tailoring to blacksmithing on my warlock and go tailoring on my rogue in stead. Ultimately I don’t think min-maxing this choice matters too much, but I also don’t expect to have the time to farm tons of Spirits, so I will rely on non-spirit recipes like prospecting, alchemy and PvP crafts for the most part.