Crafting professions are already very well known for providing the unmistakable ability to add buffs to all characters. No one takes a serious raider very seriously if their gear isn't enchanted, for example, or if they're not sporting a stylish and effective Eternium Belt Buckle.
However, the vast majority of crafted character enhancements can be bought and sold on the Auction House. To help make professions a more meaningful choice, every profession has some non-transferable benefit to a character. Maybe they have access to superior versions of certain items (like Jewelcrafter-only Dragon's Eye gems), or a particular enchant that no one else can use (like ring enchants.)
Trying to choose which profession is best for your character can be difficult. Granted, it's pretty easy to see some obvious, immersive choices. Most Tailors I know, for example, are some kind of a cloth class. But if you're trying to base your character's profession choice on which of the unique-to-crafter benefits give you the most bang for your buck, it's going to get a little more difficult.
Let's take a look behind the jump and start discussing the crafter-only augments that come with each profession.
Just like the crating professions, the gathering professions each supply the character with a unique, significant bonus. Those bonuses have even been buffed in past patches, to help keep them up-to-date and relevant within the contemporary raiding environment. And, of course, each one is different.
Herbalism: Lifeblood is one of the more interesting augmentations available from professions. While in most situations, it might just seem like a free healing potion, there are a couple things that make it better than that. First, it's not a potion, and doesn't share a cooldown. Second, you can use it while in stealth. That's a not-insignificant advantage if you're the kind to drop into stealth to get a second shot at an opponent.
Mining: Toughness provides your level 80 character 60 Stamina. This got a ten-point buff in patch 3.2; before that, it had only buffed your Stamina by 50 points. This amount of stamina is nothing to sneeze at; the only reason it would be called into doubt is if another profession provided a greater buff for its purpose.
Skinning: Skinning provides you a resounding 40 Critical Strike Rating at level 80, which translates to a little less than a 1% crit chance. Master of Anatomy is therefore pretty nice, but shares the same problem as Mining: if another profession provides a greater buff to that purpose, you might want to check out those pastures. So with that in mind, let's get into the manufacturing professions, and see what bonuses they provide.
The basic benefit of any manufacturing profession is that "you can use the stuff you make." Still, for the purposes of this article, we're talking about the unalienable bonuses or abilities provided to only the crafter with the profession.
Alchemy: Alchemy's big exclusive buff is mostly Mixology, which provides an extra benefit when you chug flasks and elixirs. Also, there are a few "Endless" potions (of the Mana and Health varieties) that you can use over and over without ever consuming the item. It's pretty nice, but unless you find yourself need to use such a potion every single encounter, that's a pretty situational bonus. Of course, there's the Flask of the North which you can use in the Arena. Awesome, but there's no Stamina component to the Flask.
Blacksmithing: While the belt buckle is awesome, everyone can use one. The real benefit of Blacksmithing comes in that you get to pick up two additional gem slots, inserting them into bracers and gloves. This is an astounding benefit, not only because of raw stat potential, but because of the customization of this ability. You could choose to gem these slots for crit, haste, hit, stam, dodge, parry, and any other combination available. This customization lets you really fine tune your kit in ways no other profession allows.
Enchanting: Enchanting's unique bonuses come in the form of ring enchants. You can pick up bonus attack power or spell power on your rings. The options are 40 attack power per ring or 23 spell power per ring. These are unique and powerful buffs to your character. These seem to win out over the Alchemy bonuses, since you can still use other elixirs while having these ring enchants. The Flask of the North uses up your available "flask slots."
Engineering: Engineering is constantly a unique snowflake, and continues to be so when we talk about character buffs. I'd recommend checking out Amanda Miller's excellent analysis of Engineering in patch 3.2, since that will really help you make your decision about the profession. Being an engineer is a highly personal choice, and engineers are often fanatically loyal to their profession.
Inscription: Scribes are able to produce and use unique shoulder enchants known as Master's Inscriptions. The most important benefit of these shoulder enchants is that the scribe doesn't have to suffer the Sons of Hodir grind. Really, it would be worth it to be a scribe for that benefit alone. Still, the Master's Inscriptions are a little better than what non-scribes can access. The Master's Inscriptions are worth about 80 Attack Power, 46 Spell Power, or 40 Dodge Rating more than the universally available versions.
Jewelcrafting: Gems are a mainstay of end-game gear. Many high-end items have gem slots, in which epic gems provide even greater power. Jewelcrafters get to use super-duper epic gems, called Dragon's Eye gems. To give a good frame of reference, the Bold Cardinal Ruby is the best Strength related gem in the game that's available to everyone. However, the Bold Dragon's Eye gem provides 14 more Strength that its counterpart. A Jewelcrafter can equip up to three Dragon's Eye gems, though they can mix and match the various gem colors.
Leatherworking: If you like to make stuff out of leather, you can add fur lining to your bracers. Am I the only one who gets images of fuzzy handcuffs whenever talking about this bonus? At any rate, the fur lining available to leatherworkers provides 130 Attack Power, 76 Spell Power, or 102 Stamina to your bracers. That sounds like a lot until you realize that you can't use other enchants when you're using fur lining. Your net gain for each of these options are only 80 Attack Power, 47 Spell Power, or 60 Stamina. The leatherworking benefit, therefore, is completely in line with what we see from the other manufacturing professions in their own right.
Tailoring: Tailors have a few unique spellthread options, which make their pants a little better. However, those items are reproduced in other patterns useable by everyone (albeit, for more expensive materials.) Tailor's only unique buffs come in the form of special cloak enchants, called Embroidery. Unlike everyone else's profession-specific bonus abilities, Embroidery benefits all come in the form of a proc. They can either grant you mana, bonus Spell Power, or bonus attack power. While these benefits are nice, they're generally not considered as reliable as the more constant benefits from other professions.
So, in summary, Blizzard's done a pretty good job of making all the professions relatively equal in terms of exactly how much each grants your character. You can expect about 80 Attack Power, 47 Spell Power, or maybe 60 Stamina from each profession. However, the real question is which combination is best. You can double up on that per-profession bonus by choosing wisely.
Common wisdom is that Blacksmithing and Jewelcrafting combine to provide the best overall bonuses to characters. This is because not only do you get to use the Dragon's Eye gems, but you get two extra gem slots for other epic gems. I'd say, though, it's more about the specific flexibility of that combination -- you can pick and choose the exact stats you need, at any given gear time.
We'll cover more about the Blacksmithing/Jewelcrafting combination next week, now that we have this basic framework to build on. Ultimately, I think a lot of people still prefer to choose their professions based on immersion reasons. After all, a warrior who enchants stuff and sews pretty robes just seems kind of ... weird.