Mages are the most powerful dps caster class in World of Warcraft. They have no healing abilities and they are one of the best damage dealers. Mages armor is made from cloth and they can’t wear any other material.
Tailoring and Enchanting
This is a very common combination for Mages since they wear cloth. With these two professions, Mages will always have an advantage while leveling since they can craft their own armor. On the higher levels they will be able to craft the pre-raiding gear and also while raiding they will be able to learn BOP (bind on pickup) patterns which they can claim. A tailor Mage can also make parts which will improve his gear like embroidery for pants. If you would buy these from another tailor it would cost you gold and valuable mats, but if you are a tailor yourself it will only cost you two Ethernium threads. Same thing goes for cloak improvements you can make for yourself.
The Enchanting profession is also very useful for a Mage. Mages can use it to enchant their gear easily, disenchant all the unwanted and not needed items which of course they can sell, use for their own enchants or use to level up tailoring. There are also ring enchants that only enchanters can put on their rings such as +19 spell power. It is also nice to be able to enchant all of your other gear pieces that could be enchanted, because in any other case you will have to pay for it, and the mats are quite expensive. A Mage without enchants wouldn’t perform as good as the one that has fully enchanted gear.
Alchemy and Herbalism
Having Alchemy and Herbalism is nice for any character and Mages are no exception. Since they are top damage dealing casters they use flasks, potions and spell power elixirs. These goodies are quite expensive on the Auction House and by having these two professions Mages will not only save up some gold, but would always be prepared for the fight with their stats increasingly boosted. Another nice thing for a Mage will definitely be the Life Blood buff which they will get with Herbalism. For a Mage which doesn’t have a single healing spell this would be awesome. Life Blood will heal the Mage for 2000 over 5 seconds and it can be used while your char is invisible or stealthed.
A Mage could also choose to train Jewelcrafting since crafting rare gems is also really nice. Mages that have Jewelcrafting would be able to craft unique equip gems which would improve the stats on their armor. Engineering could be nice because of the head piece of armor popularly called goggles. As an Engineer you can make other useful items such as injectors for healing and mana potions which are used to save you some space in the bag where you would probably have a lot of pots. Inscription is a useful profession as well because of the nice glyphs you could make for yourself.