For the last 5 years I have been an Enchanter and a Jewelcrafter.
I am usually on a very populated server, so there isnt really much money in owning the recipes though, so whenever a new xPac hits, I never buy the recipes I sell the tokens (JC) or the mats (ench).
Lately ive been thinking about the relevance of my professions though.
For Enchanting, I make constant small money every time I upgrade some gear. Questing in the early xPac yields thousands if not 10s of thousands of gold in mats as well.
I am fairly happy with this.
But Jewelcrafting... the only thing I use it for are the personal gems. and in the last 2 xpacs, selling the tokens. Even in this expansion, the cost to research a recipe far far outweights the benefits of owning it since 100s of people are selling the gems.
As much as I hate to admit it, I think I should drop jewelcrafting and pick something else.
I wouldnt ever be bothered to go out and look for mines or herbs except for when Im, on dailys, so im not sure how effective it would be to have either of those.
Inscription I see no point in having at all, unless im missing something, its pretty useless.
Tailoring - I can see the perks of boosted cloth drops and also the ability to make the expensive cloths on cooldowns.
Blacksmithing, Leatherworking - No benefits to me really
Skinning - Theres always things to skin, not sure if the moneys worth it over tailoring though
Alchemy - I dont know enough about the personal boosts to judge, but im guessing it takes expensive materials to research and on a full server, I cant imagine theres much difference in material to pot prices
Engineering - Fun... but is it worth it?
Honestly what I do when new expansions come out is level my Jewelcrafter and Enchanter first. Make the cheapest items with JC then DE them. Sell the enchanting mats and if I get any blue quality items from JC then I sell them. I am not to sure how it will work for WoD but for the past 3 expansions it has made me rich.