Want to become a GMC eh? Well it's a long road, but achievable if you're persistent.

The longest road will be getting 50 complete styles. So start your journey there early.

Lots of them come from daily quests, so I'd recommend you start by doing one of those (or more if you've got multiple useful
toons).

This will let you farm for them, while making profit on sold duplicates (in traders). When you're getting close to the end, you may want to just buy the remaining parts rather than hope for RNGesus to bless you. Either way, complete a set, and move on to the next.

The second longest part will be research. This is super easy if you know someone who has all the traits researched, as you can just get them to make you what you need. Having points in the passive that increases how many you can research at a time as well as reducing the time it takes to learn helps.

Would recommend starting with the useful traits (divines, infused, precise, sharpened, training) then move into less useful ones (defending, powered, charged, decisive, invigorating).

The most difficult non-jewelry trait to make will be nirnhoned. Lots of people will make you the gear you need if you provide them the nirncrux. (Potent for weapons, Fortified for armor).

Technically I think you only need to max out 1 line fully to get the achievement for GMC, but I'd recommend you fill out the whole chart regardless. Will need them for making master writs down the road.

Provisioning has lots of extra perks for playable characters like extra time for food and drink, so those are good if you are playing with them. I don't bother on my crafting alts, since they don't typically do anything but the daily crafting writs.

After that, I generally start upgrading the skill lines by deconning everything I can. Jewelry takes the longest. It would go faster if I let my alts decon green or better rings/amulets, but I have my main do those so I can get their very precious grains.

I generally do both provisioning and alchemy last on my alts as well, since they can be power levelled by creating a large amount potions/recipes.

As for alts specifically, I use a bit of a waterfall technique. I put them in order, and then when the first one fills up a skill to 50, I start letting the next in line decon that type of item. Use the bank to hold all the intricates you pick up.

For daily writs, I tend to pre-craft on my non-played toons. Essentially I make 7 days worth of gear, and then all I need to do is log in, pick up the dailies, and then drop them off. Repeat. End of the week, I clean out all my boxes, and then at the start of the next week, I pre-craft 7 days again.

I also try to get them to level 50 as quick as possible, since that's where they make the most gold for dropping off the quests.

Wrote an article about it here: https://hirelingwanted.com/daily-crafting-writ-guide/

Hope that helps!