Classic has some extremely strong and very expensive recipes available for crafters. The most notable one of course being the Lionheart Helmet.
Getting the recipes
Most of these high-end recipes are either raid drops, random world drops or reputation rewards. The first two groups are only going to be available to you either if you are in a guild and have the reputation to get the recipe, or if you have the gold to buy them on the open market. For reputation recipes you can of course get them yourself, you just have to put in the required time to farm reputation.
Players prefer famring their own materials
What I’ve seen is that players prefer farming their own materials and getting someone to craft for them. As such you should not craft these yourself and post them to the AH. Farming materials feels more split up for players, so they prefer doing it this way, even if it is the same amount of work. To get sales you need to use trade chat. Make a macro to advertise your services. You can post your price or conditions as well. Some people go tip based models, others ask for a specific fee. I would personally lean towards asking for a fee, particularly if you have to buy the recipes, but if you get them for free you can of course do it based on tips.
Materials are expensive so reputation matters a lot!
If you are crafting a Lionheart Helm for someone they have to trust you with all the materials. You need to be 100% trustworthy and keep your word. Being in a reputable guild will help you a lot by making you more trustworthy by association. Being active in trade chat is also important, be a fixture, and you will seem more reputable as well.
How much should you charge
Usually I aim for 20% profit margin when crafting, but in thse cases I take the risk by buying the materials. When someone else provides the material I think a lower fee is reasonable. I would aim somewhere in the 5-10% of the material value range. Of course if the recipe is rare and you know you have little competition you are free to adjust your price up. Just remember that your realm may remember, so going for a lower price may help you get customers long term.
Notable recipes
So let’s take a look at some of the most notable recipes. We will focus on recipes that are out already, or ones that are coming in phase 3, which is just a couple of weeks away. This list will not be comprehensive, but a taste of some of the high profile ones that it makes sense to sell in trade chat, rather than on the ah.
Blacksmithing
Lionheart Helm: This is the most wellknown one. The helmet is amazing for warrior DPS and stays relevant for a very long time. The recipe is a random world drop and probably quite expensive to buy. At this point it is also likely your realm has multiple crafters and the value may have crashed. Outside of getting it as your guild crafter this recipe may not be worth it if you have to buy it.
Nightfall: Thorium Brotherhood recipe with a unique debuff that is very useful in raids.
Tailoring
Flarecore Wraps: BiS or close to it for healers, Drops from MC bosses.
Flarecore Robe/ Leffings: potentially useful PvP items for casters available from Thorium Brotherhood rep (Honored / Revered) in Phase 3.
Leatherworking
Corehound Belt: New Leatherworking belt from Thorium Brotherhood Revered that is phase 3 Best in Slot for Druids and Paladins.
Hide of the Wild is the current BiS healer cape and drops from Knot Thimblejack’s Cache in Dire Maul.
Enchanting
Enchanting has a lot of rare recipes that you can only sell as crafts. +4 stats, crusader, the upcoming +15 agility and other recipes are all well worth it and will remain relevant and useful for a very long time. The weapon enchants are the overall most expensive ones and the ones with by far the most power so they should be your number one priority.
Go out hunting for more!
For more ideas check your classes BiS lists, or compare craftable items to popular items. There may be crafts that are not on the BiS-list, but are close enough that they could be a better option in terms of time required, if you find an item like this do not be afraid to advertise it in trade chat. You will probably know your own class best, so start there, then expand. You can also just focus on whichever crafting profession you have and look at all available crafts to see if they could fit into someone’s gearing plans. Some players are willing to spend gold on upgrades even if they are not BiS (I am one of those players).