Go to the main city in the first zone for your alliance and talk to the NPC with a Quest Arrow above their head in the Mages Guild and Fighters Guild about Writs. IIRC, it is Fighers for Eq and Mages for Consumables, but you need them all so find both. Do the jobs they want or just tell them to Certify you, which if your L50, that is the route you want to take.

Then, in or near every crafting area is a Board for each type of Writ, Consumable or Equipment. Grab the writ, make the stuff. I highly recommend the Lazy Writ Crafter addon if your on PC. If your on console, well, slog them out. Turn in the stuff you are told to make to some city in your base Alliance, although top end writs are probably going to Belkarth.

Now, you can do writs on a completely unskilled character, they will just be L1 Materials. But, the Master Writ, the ones you need for Furniture and such, may have issues as you need to know lots of traits and lots of motifs to get a better chance to get a Master Writ and be able to work with Tempers efficiently to do them. I don't know if you can send the Master Writ to your Crafting Alt or not, but if you can, send them up to a better crafter, not down to a less skilled crafter.
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