I've been checking all over and I can't seem to get my hands on any of this stuff...I wana burn stuff. :P But in all seriousness I wish I could find some.
find a granite wall.
hit auto run.
watch the resources tab...give it 10-15 mins you'll get flint to pop up.
evidently the game does a 'check' on the resource your toon is on at a given interval.
you could probably just stand there...but doing the autorunw ill at lease raise your running some