Ok so tonight before raid I had to make pots for a lot of people in my guild because I'm pot specc'd alchemist. It's not a big deal, until you get 3-4 people asking you to make them 100+ pots each. 100 pots takes roughly 6 mins to make. These people always double pot, and are around every raid so they run out at almost the same time. I felt like I was playing my mage again in vanilla wow making water for dozens of people before each raid.
I don't really mind it much, it's why I chose pot spec, because it was the 1 spec not many people in my guild had and I was doing it to help people out. I like doing it for people, and although it may sound boring to some, having a pot crafting duel with another player can be somewhat exciting.
The chef's hat makes it so you cook foods at .5 seconds each. Very useful for those people who spent the time expanding their cookbook and cook foods for people before raid. Although it's not as useful these days with fish feasts, it still has it's uses for dedicated cooks.
So I had plenty of time to think about this while I was reaching my 20 minute mark of just making pots for people. Why isn't there a "Chef's Hat" equivalent for other professions? It wouldn't be all that complicated. So I tried to come up with a few ideas.
Alchemy - Inscription
Mortar and Pestle - Allows you to mill herbs faster resulting in reduced crafting times for potions (and elixirs) and milling herbs.
Workbench
Summons a workbench for 10 mins that allows you to craft alchemy and inscription items at a reduced rate.
I couldn't really think of anything for other professions, maybe an "Expert Crafting Hammer" or something for all the blacksmithing metals, or "Heat Resistant Gloves" that allow you to smelt faster. You could make these items either craftable, found through archaeology, or maybe some sort of questline that only lvl 85 max-level professions could do. Crafting items slowly just seems like an out of date mechanic that could use some sprucing up, and I see absolutely no negative effect on having these items.