i was able to do both (with both LW and Tailoring) from day1 on EU
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I set out to find the Engineering plan on patch day -- so long as you have 600 Engineering, you can loot it from any mob in Pandaria. The drop rate seems pretty high; I got mine within 5 minutes of killing normal mobs in Vale of the Eternal Blossom. Learning the plan will give you the schematics for all the 5.4 Engineering items, including the recipe for the new daily craftable that's used as a reagent in most of them.
I can't say the same for the other items, but I would assume that it would be a similar story.
Sometimes rnd is a PITA, the engineering ones dropped 1st mob, but on my main tailor I ended up back in Pandaria AOEing mobs for 20 minutes to get the tailoring one. On my second tailor it took an hour on the TI before it dropped.
i can only recommend the turtles in valley of the four winds people used to (and i think still are) farming for motes, leather and turtle meat. I spent 1 hour farming various high level mobs on my main to get the recipes, and then got it on the 5th or 6th turtle. Repeated on all of my alts.
Siege of Orgrimmar wing 2 has a lot of NPCs and I got lots of GlyphTechniques