Level 3 workshop requires that you turn in items to the lady near the AH in enclave. There is a quest that you are given that will track your progress. Your need 50K credits to rank up the workshop to 3 and 5mil credits to rank it up to max level 4. In her commission your see all the items that you can craft and these items do change from day to day. My advice is to craft workman's cordial +1 items to turn in. Your need to craft 2,500 of them to get the 50K credits required. They are easy to craft and cost less unlike the other stuff that are crafted. Anyways once you get the quest done that means once you traded in enough items to obtain 50K credits your be able to rank the workshop up to 3 and do a short few quest and then be given the last credit quest for 5 mil credits. Which you can craft the same item to reach that number. I guess it should also be said that if you are wanting to you can also trade in your AD to reach the credits you need. You can also use the credits you get from trading in old tool's to get credits as well. Unless you are wanting to waste your own AD my advice is take time and make that 1 item and sooner or later your get it. Just dont assume it will be done in a month it may take you a bit longer.
Answers
> I have been making the stuff for the auction house is there something else I should be doing ?
Go on google and loom up